<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>1231w</title>
<style type="text/css">
*{margin:0;padding:0;}
ul,li{list-style-type:none;}
img{border:0;}
.wrapper{800px;margin:0 auto;}
.wrapper p{line-height:30px;}
.wrapper input{height:20px;line-height:20px;}
</style>
</head>
<body>
<div class="wrapper">
<form>
<p><label>身高：</label><input type="text" value="" name = "length" id="af"/></p>
<p><label>体重：</label><input type="text" value="" name="weight"/></p>
<p><label>BIM：</label><input type="text" value="" name = "bim"/></p>
<p><label>状况：</label><input type="text" value=""/></p>
</form>
</div>
<script type="text/javascript">
var oLength = base().getName("length")[0];
var oWeight = base().getName("weight")[0];
var oBim = base().getName("bim")[0];
var flag = false;
oLength.onkeydown = oWeight.onkeydown = function(e){
var oEvent = e || window.event;
if(oEvent.keyCode !=8 && (oEvent.keyCode < 47 || oEvent.keyCode > 58) && (oEvent.keyCode < 95 || oEvent.keyCode > 106) ){
flag = false;
if(oEvent.preventDefault){
oEvent.preventDefault();
}else{
oEvent.returnValue = false;
}
}else{
if(this.value < 3){
flag = true;
}else{
if(oEvent.preventDefault){
oEvent.preventDefault();
}else{
oEvent.returnValue = false;
}
}
}
}
oLength.onkeyup = oWeight.onkeyup = function(){
if(flag == true ){
oBim.value = oLength.value * oWeight.value;
}
}
function base(){
return {
getId:function(vArg){
var arr = [];
for(var i=0;i<vArg.length;i++){
arr.push(document.getElementById(vArg[i]));
}
},
getName:function(vArg,parent){
var parent = parent || document;
return parent.getElementsByName(vArg);
}
}
}
</script>
</body>
</html>