注意，由于涉及到中线问题，所以字号会影响对齐的效果。例子就不举了，你可以改变字号（12px、13px等）自己尝试一下。
css 特殊input样式，参考如下：
输入框景背景透明：<input style="background:transparentborder:1px solid #ffffff">
鼠标划过输入框，输入框背景色变色：
<INPUT value="Type here" NAME="user_pass" TYPE="text" SIZE="29" onmouseover="this.style.borderColor='black'this.style.backgroundColor='plum'"
style="width: 106 height: 21"
onmouseout="this.style.borderColor='black'this.style.backgroundColor='#ffffff'" style="border-width:1pxborder-color=black">
输入字时输入框边框闪烁(边框为小方型)：
<Script Language="javascript">
function borderColor(){
if(self['oText'].style.borderColor=='red'){
self['oText'].style.borderColor = 'yellow'
}else{
self['oText'].style.borderColor = 'red'
}
oTime = setTimeout('borderColor()',400)
}
</Script>
<input type="text" id="oText" style="border:5px dotted redcolor:red" onfocus="borderColor(this)" onblur="clearTimeout(oTime)">
输入字时输入框边框闪烁(边框为虚线)：
<style>
#oText{border:1px dotted #ff0000ryo:expression(onfocus=function light (){with(document.all.oText){style.borderColor=(style.borderColor=="#ffee00"?"#ff0000":"#ffee00")timer=setTimeout(light,500)}},onblur=function(){this.style.borderColor="#ff0000"clearTimeout(timer)})}
</style>
<input type="text" id="oText">
自动横向廷伸的输入框：
<input type="text" style="huerreson:expression(this.width=this.scrollWidth)" value="abcdefghijk">
自动向下廷伸的文本框：
<textarea name="content" rows="6" cols="80" onpropertychange="if(this.scrollHeight>80) this.style.posHeight=this.scrollHeight+5">输入几个回车试试</textarea>
只有下划线的文本框：
<input style="border:0border-bottom:1 solid blackbackground:">
软件序列号式的输入框：
<script for="T" event="onkeyup">
if(value.length==3)document.all[event.srcElement.sourceIndex+1].select()
</script>
<input name="T" size="5" maxlength="3">—<input name="T" size="5" maxlength="3">—<input name="T" size="5" maxlength="3">—<input name="T" size="5" maxlength="3">—<input name="T" size="5" maxlength="3">—<input name="T7" size="5" maxlength="3">
<!DOCTYPE HTML><html>
<meta charset="UTF-8">
<title>test</title>
<head>
<style type="text/css">
body {
margin: 0 auto
text-align: center
font-family: "微软雅黑"
}
.normal {
background: url(http://pic.58pic.com/58pic/14/82/90/81B58PIC52m_1024.jpg) no-repeat
background-size: 6px
background-position: 95% 45%
}
.error {
background: url(http://static7.depositphotos.com/1222693/712/i/170/depositphotos_7122979-Red-button.jpg) no-repeat
background-size: 9px
background-position: 95% 45%
border-color: red
}
.warning {
visibility: hidden
font-size: 12px
background: red
color: white
padding: 1px
margin-left: 5px
}
</style>
<script type="text/javascript">
window.onload = function() {
var myinput = document.getElementById('myinput')
var myspan = document.getElementById('myspan')
//失去焦点事件
myinput.onblur = function() {
if(!myinput.value || isNaN(myinput.value)) {
this.className = 'error'
this.title = '请输入此字段'
this.focus()
myspan.style.visibility = 'visible'
} else {
this.className = 'normal'
this.title = ''
myspan.style.visibility = 'hidden'
}
}
}
</script>
</head>
<body>
<div>
<input class="normal" type="text" id="myinput" /><span id="myspan" class="warning">请输入数字</span>
</div>
</body>
</html>
