<html>
<head>
<title> New Document </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>
<script type="text/javascript">
<!--
window.onload = function(){
document.getElementsByTagName('button')[0].onclick = function(){
// 不能有相同取值的下拉列表集合
var items = document.getElementsByTagName('select'),
len = items.length,
i = 0,
valMap = {},
sel,
val
// 遍历并保存各个下拉列表的值于valMap
for( i < len i++){
sel = items[i]
val = sel.options[sel.selectedIndex].value
// 没有相同的取值时保存该值，否则返回false
if(!valMap[val]){
valMap[val] = 1
}else{
alert('存在取值相同的下拉列表，取值为：' + val)
return false
}
}
// 校验通过，全部都不相同
return true
}
}
//-->
</script>
<body>
<button>Check</button>
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
<select>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
</body>
</html>
看你的意思是只能输入1.0-10.0的数<input type="text" onchange="limitInput(this)" />
<script type="text/javascript">
function limitInput(o){
//Number()方法能保留小数点后的值,你用parseInt(),如果输入10.1，会变成10
var value = Number(o.value)
if( value<1 || value>10){
alert("请输入1-10之间数字")
o.value=""
}else{
//匹配1.0-10.0的数
var reg = new RegExp(/^\d{1,2}(\.\d)?$/)
if(reg.test(value)){
return true
}else{
alert("输入错误！")
return false
}
}
}
