AJAX之xmlHttp

　　        //var xmlHttp = new ActiveXObject(MSXML2.XMLHTTP);
　　        xmlHttp.open(POST, webFileUrl, false);
　　        xmlHttp.setRequestHeader(Content-Type,application/x-www-form-urlencoded);   
　　        xmlHttp.send();　　    　　       
　　               
            xmlHttp.onreadystatechange=function()
            {
                if (xmlHttp.readyState==4)
                {
                    result = xmlHttp.responseText;
                }
            }
            if(xmlHttp.status!=200)
            {
                alert (网络故障(xmlHttp.status=+xmlHttp.status+)，请稍后再试！);
            }
               
            result = xmlHttp.responseText;　
　　        result = result.substring(0,result.indexOf(?EX));
　　       
　　        if(result != false)
　　        {　　　　       
　　　　        return true;
　　        }
　　        else
　　        {
　　　　        return false;
　　        }
        }
        //-->
    </script> <summary>
检测用户是否存在<文件名：../User/CheckUser.aspx>
</summary>
<remarks>Created by dzh @2006/06/27 18:22</remarks>
Partial Class Web_User_CheckUser
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Request.QueryString(LogonName) Is Nothing Then
            Response.Write(false + ?EX)
            Response.End()
            Exit Sub
        End If

        If (New EasyClick.EasyBusiness.UserBusiness).GetUserByLogonName(Request.QueryString(LogonName).ToString) Is Nothing Then
            Response.Write(false + ?EX)
            Response.End()
            Exit Sub
        Else
            Response.Write(true + ?EX)
            Response.End()
            Exit Sub
        End If
    End Sub
End Class