求解啊！！一直显示count is not defined at HTMLInputElement.onclick
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var = txt;
//获取第一个输入框的值
var a = document.getElementById("txt1").value;
//获取第二个输入框的值
var b = document.getElementById("txt2").value;
//获取选择框的值
var c = document.getElementById("select").value;
//获取通过下拉框来选择的值来改变加减乘除的运算法则
switch(c){
case "+":
txt = parseInt(a) + parseInt(b);
break;
case "-":
txt = parseInt(a) - parseInt(b);
break;
case "*":
txt = parseInt(a) * parseInt(b);
break;
case "/":
txt = parseInt(a) / parseInt(b);
break;
}
//设置结果输入框的值
document.getElementById('fruit').value=txt;
}
</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' onclick='count()' value=' = ' /> <!--通过 = 按钮来调用创建的函数，得到结果-->
<input type='text' id='fruit' />
</body>
</html>
看了半天了还是找不到哪错了！！
删掉这个就可以
