无法得到结果
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var x=document.getElementById("txt1").value;
var y=document.getElementById("txt2").value;
var z=document.getElementById("select").value;
var result;
switch(select){
case "+":
result=x+y;
break;
case "-":
result=x-y;
break;
case "*":
result=x*y;
break;
case "/":
result=x/y;
break;
}
document.getElementById("fruit").value = 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()" /> <!--通过 = 按钮来调用创建的函数，得到结果-->
<input type='text' id='fruit' />
</body>
</html>
