<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> </head> <head> <script> function validateForm(){ var x=document.forms["myForm"]["fname"].value; if (x==null || x==""){ alert("姓必须填写"); return false; } } </script> </head> <body> <form name="myForm" action="demo-form.php" onsubmit="return validateForm()" method="post"> 姓: <input type="text" name="fname"> <input type="submit"</>= "submit"value form> </body> </html>
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> </head> <head> <script> function validateForm(){ var x=document.forms["myForm"]["email"].value; var atpos=x.indexOf("@" ); Var dotpos = x.lastIndexOf ( " . " ); IF (atpos < . 1 || dotpos < atpos + 2 || dotpos + 2 > = x.length) { Alert ( " is not a valid e-mail address " ); return to false ; } } </ Script > </ head > < body > < form name =" myForm " action="demo-form.php" onsubmit="return validateForm();" method="post"> Email: <input type="text" name="email"> <input type="submit" value="提交"> </form> </body> </html>
