跪求哪里错辣。。。。
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<script type="text/javascript">
function count(){
var a = document.getElemenById("txt1").value;
var b = document.getElemenById("txt2").value;
var c = document.getElementById("select").value;
var d;
switch(c){
case "+":
d = a + b;
break;
case "-":
d = a - b;
break;
case "*":
d = a * b;
break;
default:
d = a / b;
break;
}
document.getElementById("fruit").value=d;
}
</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>
