请问我的代码哪里有错，点击没反应
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var s="";
var x=document.getElementById("txt1").value;
var y=document.getElementById("txt2").value;
var z=document.getElementById("select");
switch (z){
case "+":
s=parseInt(x)+parseInt(y);
break;
case "-":
s=x-y;
break;
case "*":
s=x*y;
break;
default:
s=x/y;
}
doucument.getElementById("fruit").value=s;
}
</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>
