哪里错了呢 又看不出来啦╮(╯▽╰)╭
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var x=parseInt(document.getElementById('txt1').value);
var y=parseInt(document.getElementById('txt2').value);
var how=document.getElementByI('select').value
var result='';
switch (how)
{
case '+':
result=x+y;
break;
case '-':
result=x-y;
break;
case '*':
result=x*y;
break;
case '/':
result=x/y;
break;
}
result=document.getElementById('fruit').value;
}
</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()" />
<!--通过 = 按钮来调用创建的函数，得到结果-->
<input type='text' id='fruit' />
</body>
</html>
