没有输出哪错了？
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var shu1=document.getElementById("txt1").value;
var shu2=document.getElementById("txt2").value;
var fh=document.getElementById("select").value;
var jieguo="";
switch(fh){
case "+" :
jieguo=parseInt(shu1)+parseInt(shu2);
break;
case "-" :
jieguo=parseInt(shu1)-parseInt(shu2);
break;
case "*" :
jieguo=parseInt(shu1)*parseInt(shu2);
break;
default:
jieguo = parseFloat(shu1) / parseFloat(shu2);
}
document.getElementById("fruit").value = jieguo;
}
</script>
</head>
<body>
<input type='text' id='txt1' />
<select id='select'>
<option value='+'>+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select>
<input type='text' id='txt2' />
<input type='button' value=' = ' onlick="count()"/>
<input type='text' id='fruit' />
</body>
</html>
