为什么我的加法运算不对
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count()
{
var text1=document.getElementById("txt1").value;
var text2=document.getElementById("txt2").value;
var v=document.getElementById("select").value;
//设置结果输入框的值
switch(v)
{
case "+":
var result = text1 + text2;
break;
case "-":
var result = text1 - text2;
break;
case "*":
var result = text1 * text2;
break;
case "/":
var result = text1 / text2;
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>
