一个关于列表框的问题，急～～

<!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=utf-8" />
        <script>
            function $(id){
                return document.getElementById(id);
            }
            
            function Validation(obj){
                if (obj.value == null || obj.value == "") 
                    return;
                var se = $("se").value;
                var r;
                switch (se) {
                    case "1": //处理输入的内容
                        r = /^[\u4E00-\u9FA5\uF900-\uFA2D]*$/g;
                        break;
                    case "0": //处理输入的内容
                        r = /^\d*$/g;
                        break;
                }
                if (!r.test(obj.value)) {
                    alert("输入错误！");
                    setTimeout("$('" + obj.id + "').focus();", 1);
                }
            }
        </script>
    </head>
    <body>
        <select name="select" onChange="" id="se">
            <option value="1">name </option>
            <option value="0">class </option>
            <option value="0">number </option>
        </select>
        <INPUT id="txt1" name="input" TYPE="text" onkeyup="Validation(this)">
    </body>
</html>