请问为什么运行结果出不来呢
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var x,y,result,o;
x=document.getElementById('txt1').value;
//获取第一个输入框的值
y=document.getElementById('txt2').value;
//获取第二个输入框的值
o=document.getElementById('select').value;
//获取选择框的值
switch(o){
case "+":
result=parseInt(x)+parseInt(y);
break;
case "-":
result=parseInt(x)-parseInt(y);
break;
case "*":
result=parseInt(x)*parseInt(y);
break;
default:
result=parseInt(x)/parseInt(y);
}
document.getElementById('fruit')=result;
}
</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=' = ' onClick="count()" />
<input type='text' id='fruit' />
</body>
</html>
