自已写一个程序检测,最好是用ajax方法,这样用户体验会好一些
前台:
<img src="http://img.star52.com.cn/images/xingzc02.jpg" width="97" height="25" border="0" onclick="UserChk();" />
function UserChk()
        {
            var UN=document.getElementById("txtUserName").value;
            var RexTmp=/^[a-zA-Z\d]+([\w\.\-]*[a-zA-Z\d]+)?$/;//^[a-zA-Z0-9_\u4E00-\u9FA5]+$/;/
            var Rexg=/^[a-zA-Z_0-9]+$/;//[^\x00-\x80]/;
            
            if(UN.length>=4)
            {
//                alert(RexTmp.test(UN));
                if(RexTmp.test(UN))
                {
                var ReVal=eval($NameSpace+".ISUSERBE('"+UN+"').value");
                if(ReVal=="400")
                {alert("用户已经存在");document.getElementById("txtUserName").value="";}
                else
                {alert("可以用此用户名注册");}
                }
                else
                {
                    alert(" 不能使用用户名:["+UN+"]注册\n");
                }
            }
            else
            {alert("用户名不正确,请重新输入");document.getElementById("txtUserName").value=""; }
        }
后台:
 /// <summary>
        /// 检测用户是否存在
        /// </summary>
        /// <param name="sUserName"></param>
        /// <returns></returns>
        [AjaxPro.AjaxMethod]
        public string ISUSERBE(string sUserName)
        {
            DLLUserRule DLLUR = new DLLUserRule();
            if (DLLUR.UserCHK(sUserName))
            { return "400"; }
            else
            { return "404"; }
        }
在后台写一个方法检测就好了