就是出不了结果，求大神们帮忙
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var select, value1, value2, result;
select=document.getElementById('select').value;
value1=document.getElementById('txt1').value;
value2=document.getElementById('txt2').value;
switch (select)
{case "+":
result=value1+value2;
break;
case "-":
result=value1-value2;
break;
case "*":
result=value1*value2;
break;
case "/":
result=value1/value2;
break;
}
return result;
//获取第一个输入框的值
//获取第二个输入框的值
//获取选择框的值
//获取通过下拉框来选择的值来改变加减乘除的运算法则
//设置结果输入框的值
}
</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' onclick="count()" value=' = ' / >
<input type='text' id='fruit' />
</body>
</html>
