js修改CSS样式的方法：
document.getElementById("xx").style.xxx;
“xx”--为ID名; xxx--为属性名;
下面是css与js的属性比较：
盒子标签和属性对照
CSS语法（不区分大小写）JavaScript语法（区分大小写）
border border
border-bottom borderBottom
border-bottom-color borderBottomColor
border-bottom-style borderBottomStyle
border-bottom-width borderBottomWidth
border-color borderColor
border-left borderLeft
border-left-color borderLeftColor
border-left-style borderLeftStyle
border-left-width borderLeftWidth
border-right borderRight
border-right-color borderRightColor
border-right-style borderRightStyle
border-right-width borderRightWidth
border-style borderStyle
border-top borderTop
border-top-color borderTopColor
border-top-style borderTopStyle
border-top-width borderTopWidth
border-width borderWidth
clear clear
float floatStyle
margin margin
margin-botto mmarginBottom
margin-left marginLeft
margin-right marginRight
margin-top marginTop
padding padding
padding-bottom paddingBottom
padding-left paddingLeft
padding-right paddingRight
padding-top paddingTop
颜色和背景标签和属性对照
CSS 语法（不区分大小写）JavaScript 语法（区分大小写）
background background
background-attachment backgroundAttachment
background-color backgroundColor
background-image backgroundImage
background-position backgroundPosition
background-repeat backgroundRepeat
color color
样式标签和属性对照
CSS语法（不区分大小写）JavaScript 语法（区分大小写）
display display
list-style-type listStyleType
list-style-image listStyleImage
list-style-position listStylePosition
list-style listStyle
white-space whiteSpace
文字样式标签和属性对照
CSS 语法（不区分大小写）JavaScript 语法（区分大小写）
font font
font-family fontFamily
font-size fontSize
font-style fontStyle
font-variant fontVariant
font-weight fontWeight
文本标签和属性对照
CSS 语法（不区分大小写）JavaScript 语法（区分大小写）
letter-spacing letterSpacing
line-break lineBreak
line-height lineHeight
text-align textAlign
text-decoration textDecoration
text-indent textIndent
text-justify textJustify
text-transform textTransform
vertical-align verticalAlign