JavaScript实现四则运算

编写一个带有两个变量和一个运算符的函数,调用时接收prompt输入

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>编写一个带有两个变量和一个运算符的函数,调用时接收prompt输入</title>
<script language="javascript" type="text/javascript">
function account()
{
        var op1=prompt("请输入第一个数:","");
        var op2=prompt("请输入第二个数:","");
        var sign=prompt("请输入运算符号","")
        var result;
        opp1=parseFloat(op1);
        opp2=parseFloat(op2);
        switch(sign)
        {
                case "+":
                        result=opp1+opp2;
                        break;
                case "-":
                        result=opp1-opp2;
                        break;
                case "*":
                        result=opp1*opp2;
                        break;
                default:
                        result=opp1/opp2;
        }
        alert("两数运算结果为:"+op1+sign+op2+"="+result);
}
</script>
</head>

<body>
<input name="btn" type="button" value="计算两数运算结果" onclick="account();" />
</body>
</html>