Как вызвать webmethod и показать предупреждающее сообщение

Hi,
    I am trying to give an alert message using "WebMethod",where my conditions are as follows

1.I am trying to restrict the user applying leave on "Monday" when he/She has already taken Leave on the previous friday.
2.I am geeting the details from my Database where the employees leave Details and trying to code this in WebMethod.

<pre>My cs page code:

       [System.Web.Services.WebMethod]
    public  string GetCurrentTime()
    {
        SqlConnection con = new SqlConnection(conString);
        con.Open();
        SqlCommand cn = new SqlCommand();
        DateTime date3 = System.DateTime.Now;
        DateTime date4 = System.DateTime.Now;
        DateTime date1 = System.DateTime.Now.AddDays(-6); ;
        DateTime date2 = System.DateTime.Now.AddDays(-6);
        DateTime.TryParse(txtFromDate.Text, out date1);
        DateTime.TryParse(txtToDate.Text, out date2);
        
       // string val;
       // var EmpID = "SS212";
        SqlDataAdapter da = new SqlDataAdapter(scmd);
            DataTable dt=new DataTable();
            da.Fill(dt);
            sdr = scmd.ExecuteReader();
        if (date1.DayOfWeek == DayOfWeek.Monday && date2.DayOfWeek == DayOfWeek.Monday)
        {
            string Leave = "Select EmpID ,LeaveType,LeaveFromDate,LeaveToDate,LeaveStatus from LeaveApplication Where LeaveFromDate  = '" + date1 + "' and LeaveToDate  = '" + date2 + "'";
            scmd = new SqlCommand(Leave, scon);
            
            
            
        }
        for(int i = 0; i < dt.Rows.Count; i++)
        {

            String value ;
            if ((dt.Rows[i]["LeaveStatus"].ToString() == "Accepted") || (dt.Rows[i]["LeaveStatus"].ToString() == "Pending")) 

        {
          value="";
        
        }
            else 
        {

            value = "";
        }

        }
       

        return "";       
    }




My aspx:



            <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        function ShowCurrentDate() {
            
            $.ajax({
                type: "POST",
                url: "LMSEmployee.aspx/GetCurrentTime",
                data: params,
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: OnSuccess,
                failure: function (response) {
                    alert("Please");
                }
            });
        }
        function OnSuccess(response) {
            alert("Please");

        }
        </script>