keycode 9 = Tab Tab
keycode 12 = Clear
keycode 13 = Enter
keycode 16 = Shift_L
keycode 17 = Control_L
keycode 18 = Alt_L
keycode 19 = Pause
keycode 20 = Caps_Lock
keycode 27 = Escape Escape
keycode 32 = space space
keycode 33 = Prior
keycode 34 = Next
keycode 35 = End
keycode 36 = Home
keycode 37 = Left
keycode 38 = Up
keycode 39 = Right
keycode 40 = Down
keycode 41 = Select
keycode 42 = Print
keycode 43 = Execute
keycode 45 = Insert
keycode 46 = Delete
keycode 47 = Help
keycode 48 = 0 equal braceright
keycode 49 = 1 exclam onesuperior
keycode 50 = 2 quotedbl twosuperior
keycode 51 = 3 section threesuperior
keycode 52 = 4 dollar
keycode 53 = 5 percent
keycode 54 = 6 ampersand
keycode 55 = 7 slash braceleft
keycode 56 = 8 parenleft bracketleft
keycode 57 = 9 parenright bracketright
keycode 65 = a A
keycode 66 = b B
keycode 67 = c C
keycode 68 = d D
keycode 69 = e E EuroSign
keycode 70 = f F
keycode 71 = g G
keycode 72 = h H
keycode 73 = i I
keycode 74 = j J
keycode 75 = k K
keycode 76 = l L
keycode 77 = m M mu
keycode 78 = n N
keycode 79 = o O
keycode 80 = p P
keycode 81 = q Q at
keycode 82 = r R
keycode 83 = s S
keycode 84 = t T
keycode 85 = u U
keycode 86 = v V
keycode 87 = w W
keycode 88 = x X
keycode 89 = y Y
keycode 90 = z Z
keycode 96 = KP_0 KP_0
keycode 97 = KP_1 KP_1
keycode 98 = KP_2 KP_2
keycode 99 = KP_3 KP_3
keycode 100 = KP_4 KP_4
keycode 101 = KP_5 KP_5
keycode 102 = KP_6 KP_6
keycode 103 = KP_7 KP_7
keycode 104 = KP_8 KP_8
keycode 105 = KP_9 KP_9
keycode 106 = KP_Multiply KP_Multiply
keycode 107 = KP_Add KP_Add
keycode 108 = KP_Separator KP_Separator
keycode 109 = KP_Subtract KP_Subtract
keycode 110 = KP_Decimal KP_Decimal
keycode 111 = KP_Divide KP_Divide
keycode 112 = F1
keycode 113 = F2
keycode 114 = F3
keycode 115 = F4
keycode 116 = F5
keycode 117 = F6
keycode 118 = F7
keycode 119 = F8
keycode 120 = F9
keycode 121 = F10
keycode 122 = F11
keycode 123 = F12
keycode 124 = F13
keycode 125 = F14
keycode 126 = F15
keycode 127 = F16
keycode 128 = F17
keycode 129 = F18
keycode 130 = F19
keycode 131 = F20
keycode 132 = F21
keycode 133 = F22
keycode 134 = F23
keycode 135 = F24
keycode 136 = Num_Lock
keycode 137 = Scroll_Lock
keycode 187 = acute grave
keycode 188 = comma semicolon
keycode 189 = minus underscore
keycode 190 = period colon
keycode 192 = numbersign apostrophe
keycode 210 = plusminus hyphen macron
keycode 211 =
keycode 212 = copyright registered
keycode 213 = guillemotleft guillemotright
keycode 214 = masculine ordfeminine
keycode 215 = ae AE
keycode 216 = cent yen
keycode 217 = questiondown exclamdown
keycode 218 = onequarter onehalf threequarters
keycode 220 = less greater bar
keycode 221 = plus asterisk asciitilde
keycode 227 = multiply division
keycode 228 = acircumflex Acircumflex
keycode 229 = ecircumflex Ecircumflex
keycode 230 = icircumflex Icircumflex
keycode 231 = ocircumflex Ocircumflex
keycode 232 = ucircumflex Ucircumflex
keycode 233 = ntilde Ntilde
keycode 234 = yacute Yacute
keycode 235 = oslash Ooblique
keycode 236 = aring Aring
keycode 237 = ccedilla Ccedilla
keycode 238 = thorn THORN
keycode 239 = eth ETH
keycode 240 = diaeresis cedilla currency
keycode 241 = agrave Agrave atilde Atilde
keycode 242 = egrave Egrave
keycode 243 = igrave Igrave
keycode 244 = ograve Ograve otilde Otilde
keycode 245 = ugrave Ugrave
keycode 246 = adiaeresis Adiaeresis
keycode 247 = ediaeresis Ediaeresis
keycode 248 = idiaeresis Idiaeresis
keycode 249 = odiaeresis Odiaeresis
keycode 250 = udiaeresis Udiaeresis
keycode 251 = ssharp question backslash
keycode 252 = asciicircum degree
keycode 253 = 3 sterling
keycode 254 = Mode_switch
<script >
//只能输入整数
function only_Number() {
if ((event.keyCode < 48 || event.keyCode > 57))
event.returnValue = false;
}
//只能输入数字或负数
function only_Decimals_Number() {
// alert(event.keyCode);
if ((event.keyCode < 48 || event.keyCode > 57)&& event.keyCode !=45)
event.returnValue = false;
}
//只能输入大于等于0的数字（包括小数点）
function only_Point_Number() {
if ((event.keyCode < 48 || event.keyCode > 57) && event.keyCode != 46)
event.returnValue = false;
}
function checknum(obj) {
var re = /^-?[1-9]*(.d*)?$|^-?0(.d*)?$/;
if (!re.test(obj.value)) {
alert("非法数字");
obj.value = "";
obj.focus();
return false;
}
}
</script>
使用
<script language="javascript">
function keyevent(){
if(event.keyCode==13)
alert("#$%#%#^^%");
}
document.onkeydown = keyevent;
</script>
event.keyCode值為37﹐38﹐39﹐40對應按下的方向鍵分別是 左﹐上﹐右﹐下
"javascript:if (event.keyCode < 45 || event.keyCode > 57) event.returnValue = false;");
if(event.keycode==13)就代表按下的是回车键盘
"javascript:if (event.keyCode > 45 && event.keyCode < 57) event.returnValue = false;");
<html>
<!--//this code by hongseheike-->
<head>
<script language="javascript">
ns4 = (document.layers) ? true : false;
ie4 = (document.all) ? true : false;
function keyDown(e){
if(ns4){
var nkey=e.which;
var iekey='现在是ns浏览器';
var realkey=String.fromCharCode(e.which);
}
if(ie4){
var iekey=event.keyCode;
var nkey='现在是ie浏览器';
var realkey=String.fromCharCode(event.keyCode);
if(event.keyCode==32){realkey='\' 空格\''}
if(event.keyCode==13){realkey='\' 回车\''}
if(event.keyCode==27){realkey='\' Esc\''}
if(event.keyCode==16){realkey='\' Shift\''}
if(event.keyCode==17){realkey='\' Ctrl\''}
if(event.keyCode==18){realkey='\' Alt\''}
}
alert('ns浏览器中键值:'+nkey+'\n'+'ie浏览器中键值:'+iekey+'\n'+'实际键为'+realkey);
}
document.onkeydown = keyDown;
if(ns4){
document.captureEvents(Event.KEYDOWN);}
</script>
</head>
<body>
//Javascript Document
<hr>
<center>
<h3>请按任意一个键。。。。</h3>
</center>
</body>
</html>
**********************************************************************
使用javascript在WEB页面中截获键盘输入
使用event对象的keyCode属性判断输入的键值
eg：if(event.keyCode==13)alert(“enter!”);
键值对应表
A 0X65 U 0X85
B 0X66 V 0X86
C 0X67 W 0X87
D 0X68 X 0X88
E 0X69 Y 0X89
F 0X70 Z 0X90
G 0X71 0 0X48
H 0X72 1 0X49
I 0X73 2 0X50
J 0X74 3 0X51
K 0X75 4 0X52
L 0X76 5 0X53
M 0X77 6 0X54
N 0X78 7 0X55
O 0X79 8 0X56
P 0X80 9 0X57
Q 0X81 ESC 0X1B
R 0X82 CTRL 0X11
S 0X83 SHIFT 0X10
T 0X84 ENTER 0XD
如果要使用组合键，则可以利用event.ctrlKey，event.shiftKey，event .altKey判断是否按下了ctrl键、shift键以及alt键
JS判断只能是数字和小数点
0.不能输入中文
1）<input onpaste="return false;" type="text" name="textfield" style="width:400px; ime-mode:disabled" value="">
2）<script>
function chkIt(frm){
if (frm.n1.value.length>0&&frm.n1.value.match(/[\x01-\xFF]*/)==false){
alert('n1不能输入中文！')
frm.n1.focus();
return false;
}
}
</script>
<body>
<form onsubmit="return chkIt(this)">
<input name="n1">
<input name="n2">
<input name="smt" type="submit" value="提交">
</form>
</body>
1.文本框只能输入数字代码(小数点也不能输入)
<input onkeyup="this.value=this.value.replace(/\D/g,'')" onafterpaste="this.value=this.value.replace(/\D/g,'')">
2.只能输入数字,能输小数点.
<input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')">
<input name=txt1 onchange="if(/\D/.test(this.value)){alert('只能输入数字');this.value='';}">
3.数字和小数点方法二
<input type=text t_value="" o_value="" onkeypress="if(!this.value.match(/^[\+\-]?\d*?\.?\d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.o_value=this.value" onkeyup="if(!this.value.match(/^[\+\-]?\d*?\.?\d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.o_value=this.value" onblur="if(!this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?|\.\d*?)?$/))this.value=this.o_value;else{if(this.value.match(/^\.\d+$/))this.value=0+this.value;if(this.value.match(/^\.$/))this.value=0;this.o_value=this.value}">
4.只能输入字母和汉字
<input onkeyup="value=value.replace(/[\d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[\d]/g,''))" maxlength=10 name="Numbers">
5.只能输入英文字母和数字,不能输入中文
<input onkeyup="value=value.replace(/[^\w\.\/]/ig,'')">
6.只能输入数字和英文<font color="Red">chun</font>
<input onKeyUp="value=value.replace(/[^\d|chun]/g,'')">
7.小数点后只能有最多两位(数字,中文都可输入),不能输入字母和运算符号:
<input onKeyPress="if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || /\.\d\d$/.test(value))event.returnValue=false">
8.小数点后只能有最多两位(数字,字母,中文都可输入),可以输入运算符号:
<input onkeyup="this.value=this.value.replace(/^(\-)*(\d+)\.(\d\d).*$/,'$1$2.$3')">
禁止特殊字符：
onKeyPress="if(event.keyCode < 45 || event.keyCode > 57 ) event.returnValue = false;"
只能输入汉字：
<input onkeyup="value=value.replace(/[^/u4E00-/u9FA5]/g,'')" onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/u4E00-/u9FA5]/g,''))">
style="ime-mode:disabled"禁止汉字输入法
只能输入数字：
<input onkeyup="value=value.replace(/[^/d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/d]/g,''))">
只能输入英文和数字：
<input onkeyup="value=value.replace(/[/W]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/d]/g,''))">
控制输入框只能输入文字或数字，也可以不允许输入特殊字符
这里不允许输入如下字符: (像 ^&* 等)<br>
<textarea rows=2 cols=20 name=comments onKeypress="if ((event.keyCode > 32 && event.keyCode < 48) || (event.keyCode > 57 && event.keyCode < 65) || (event.keyCode > 90 && event.keyCode < 97)) event.returnValue = false;">
只禁止空格输入
onkeyup="value=value.replace(//s/g,'')"
onkeydown="if(event.keyCode==32) return false"
只能输入中文和英文：
onkeyup="value=value.replace(/[^/a-zA-Z/u4E00-/u9FA5]/g,'')" onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/a-zA-Z/u4E00-/u9FA5]/g,''))"
不允许输入特殊字符和空格:
<input id="code" onkeypress="return ValidateSpecialCharacter();" onblur="validate(this)"/>
————————————————————————————————————————
不能为空
<input onblur="if(this.value.replace(/^ +| +$/g,'')=='')alert('不能为空!')">
判断字符由字母和数字，下划线,点号组成.且开头的只能是下划线和字母
/^([a-zA-z_]{1})([\w]*)$/g.test(str)
只能输入数字
<input name="text" type="text" id="NewPage" onKeyUp="value=value.replace(/\D/g,'')" onafterpaste="value=value.replace(/\D/g,'')" >
只能输入中文
<input type="text" onkeyup="value=value.replace(/[^\u4E00-\u9FA5]/g,'')">
只能输入英文
<input type="text" onkeyup="value=value.replace(/[^\a-\z\A-\Z]/g,'')">
<input type="text" onkeyup="value=value.replace(/[^a-zA-Z]/g,'')">
--------------------------------------------------------------------------------------------------------------------
1.文本框只能输入数字代码(小数点也不能输入)
<input onkeyup="this.value=this.value.replace(//D/g,'')" onafterpaste="this.value=this.value.replace(//D/g,'')">
2.只能输入数字,能输小数点.
<input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')">
<input name=txt1 onchange="if(//D/.test(this.value)){alert('只能输入数字');this.value='';}">
3.数字和小数点方法二
<input type=text t_value="" o_value="" onkeypress="if(!this.value.match(/^[/+/-]?/d*?/.?/d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?)?$/))this.o_value=this.value" onkeyup="if(!this.value.match(/^[/+/-]?/d*?/.?/d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?)?$/))this.o_value=this.value" onblur="if(!this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?|/./d*?)?$/))this.value=this.o_value;else{if(this.value.match(/^/./d+$/))this.value=0+this.value;if(this.value.match(/^/.$/))this.value=0;this.o_value=this.value}">
4.只能输入字母和汉字
<input onkeyup="value=value.replace(/[/d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[/d]/g,''))" maxlength=10 name="Numbers">
5.只能输入英文字母和数字,不能输入中文
<input onkeyup="value=value.replace(/[^/w/.//]/ig,'')">
6.只能输入数字和英文<font color="Red">chun</font>
<input onKeyUp="value=value.replace(/[^/d|chun]/g,'')">
7.小数点后只能有最多两位(数字,中文都可输入),不能输入字母和运算符号:
<input onKeyPress="if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || //./d/d$/.test(value))event.returnValue=false">
8.小数点后只能有最多两位(数字,字母,中文都可输入),可以输入运算符号:
<input onkeyup="this.value=this.value.replace(/^(/-)*(/d+)/.(/d/d).*$/,'$1$2.$3')">
只能输入中文、英文、数字、@符号和.符号
<input type="text" onkeyup="value=value.replace(/[^\a-\z\A-\Z0-9\u4E00-\u9FA5\@\.]/g,'')">
只允许输入英文，且不能粘贴也无法弹出粘贴菜单
<input type="text" onkeyup="value=value.replace(/[^\a-\z\A-\Z]/g,'')" onkeydown="fncKeyStop(event)" onpaste="return false" oncontextmenu = "return false"/>
只能输入数字和点号(注意:在[^\d\.]里的d不能写成大写D,否则就变成除了数字以外的所有字符)
<input name="price" type="text" size="8" maxlength="8" onkeyup="value=value.replace(/[^\d\.]/g,'')" >
总而言之:先在<input>里输入onkeyup="value=value.replace(/[^\X]/g,'')" 然后在(/[\X]/g,'')里的X换成你想输入的代码就可以了
中文：u4E00-u9FA5
数字：d、0-9
英文：a-z、A-Z
其它符号@,点或其它符号.也可以多个,用\隔开就行了.
例如:
中、英文和数字加@符号加点符号：\a-\z\A-\Z0-9\u4E00-\u9FA5\@\.
若 想在文本框里不能右键弹出菜单和不能粘贴进复制的信息的话就要在<input>里输入 onKeyDown="fncKeyStop(event)" onpaste="return false" oncontextmenu="return false;"
---------------------------------------------------------------------------------------------------------------------------------------
其一，只允许输入数字和小数点。
<input onKeypress="return (/[/d.]/.test(String.fromCharCode(event.keyCode)))" style="ime-mode:Disabled">
其二，判断的更详细一些，甚至22..2这样不算数字也判断得出来
<script>
function check(){
if (isNaN(tt.value))
{alert("非法字符！");
tt.value="";}
}
</script>
<input type="text" name="tt" onkeyup="check();">
其三，只允许输入整数。其实也完全可以根据第三条来举一反三做一些限制。
<script language=javascript>
function onlyNum()
{
if(!(event.keyCode==46)&&!(event.keyCode==8)&&!(event.keyCode==37)&&!(event.keyCode==39))
if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105)))
event.returnValue=false;
}
</script><input onkeydown="onlyNum();" style="ime-mode:Disabled">
结语,其实
style="ime-mode:Disabled"
这句是比较实用的。意为关闭输入法。省得有些人开着全角输入数字，结果输入不进去来找你哭天抹泪的，还怪你设计的不好。
只允许输入数字
<input name="username" type="text" onkeyup="value=this.value.replace(//D+/g,'')">
只允许输入英文字母、数字和下划线(以下二种方法实现)
<input name="userna其一，只允许输入数字和小数点。
<input onKeypress="return (/[/d.]/.test(String.fromCharCode(event.keyCode)))" style="ime-mode:Disabled"> 结语,其实
style="ime-mode:Disabled
这句是比较实用的。意为关闭输入法。省得有些人开着全角输入数字，结果输入不进去来找你哭天抹泪的，还怪你设计的不好。
只允许输入数字
<input name="username" type="text" onkeyup="value=this.value.replace(//D+/g,'')">
只允许输入英文字母、数字和下划线(以下二种方法实现)
<input name="username" type="text" style="ime-mode:disabled">
<input name="username" type="text" onkeyup="value=value.replace(/[^/w/.//]/ig,'')">
只允许输入英文字母、数字和&=@
<input name="username" type="text" onkeyup="value=value.replace(/[^/w=@&]|_/ig,'')">
只允许输入汉字
<input name="username" type="text" onkeyup="value=value.replace(/[^/u4E00-/u9FA5]/g,'')">
me" type="text" style="ime-mode:disabled">
<input name="username" type="text" onkeyup="value=value.replace(/[^/w/.//]/ig,'')">
只允许输入英文字母、数字和&=@
<input name="username" type="text" onkeyup="value=value.replace(/[^/w=@&]|_/ig,'')">
只允许输入汉字
<input name="username" type="text" onkeyup="value=value.replace(/[^/u4E00-/u9FA5]/g,'')">