asp.net + jquery

<script type="text/javascript">
var loginName,checkUN,password,confirmPwd,email,subBtn,userName,checkTel,tel;
$(init);
function init()
{
    loginName = $("#loginName");
    loginName.bind("blur",checkUserName);
    password = $("#password");
    confirmPwd = $("#confirmPwd");
    userName = $("#userName");
    userName.bind("blur",checkRN);
    password.bind("blur",checkPwd);
    confirmPwd.bind("blur",checkConfPwd);
    email = $("#email");
    email.bind("blur",checkEmail);
    subBtn = $("#subBtn");
    subBtn.bind("click",subUser);
    checkTel = $("#checkTel");
    tel = $("#tel");
    tel.bind("blur",chkTel);
}
function checkUserName()
{
     loginName = $("#loginName").val();
     if(jQuery.trim(loginName)=="")
        {
            $("#loginName").focus();
            $("#checkUN").css("color","Red");
            $("#checkUN").text("用户名不能为空");
            return false;
         }
      else
      {
        $("#checkUN").text("验证中...");
        $.post("checkUser.ashx?tm="+new Date().getDate()+"&loginName="+loginName,function (result){
            if(result=="0")
            {