ASP.net Error

Hi My sharepoint application geeting error below
Page Load -Index was outside the bounds of the array,Can some one show me where is error generating,
This is generating only one person machine (browser) other every one working fine. i can't debug the programme becuase its in the client side.No access at all.But i can see the error using in the error Table.( i generated Table for any error goes to that table)

 protected void Page_Load(object sender, EventArgs e)
        {
            try
            {
                LblUserLoginError.Visible = false;
                ConnectionOpen = new Site();
                LoginRights UsernameFind = new LoginRights();
            
            


                string[] CurrentUsername = UsernameFind.CurrentUserName().Split('\\');
                //=================================================================================================================================

                //  public int SalesLoginRights(string Username, string Country,out string SalesID)

             
                
                string[] HomeBackGlobal = Regex.Split(HttpContext.Current.Request.Url.ToString(), "http://");
                string Test_SalesPagePath = "~/_layouts/Test_Global/Test_Sales.aspx?Hm=" + HomeBackGlobal[1];
                //Image_Country.ImageUrl =ConnectionOpen.CountryFlag( LblCountry.Text.ToString());
                LinkDashBoard.Text = "DashBoard -" + LblCountry.Text.ToString();





                //================================================================================================================================
                //HttpContext context = HttpContext.Current;
                PropertyInfo isreadonly = typeof(System.Collections.Specialized.NameValueCollection).GetProperty("IsReadOnly", BindingFlags.Instance | BindingFlags.NonPublic);
                if (!((Page)System.Web.HttpContext.Current.CurrentHandler).IsPostBack)
                {

                    if (HttpContext.Current.Request.QueryString["SalesID"] != null)
                    {
                        string tempValue = HttpContext.Current.Request.QueryString["SalesID"].ToString();
                        LblSalesID.Text = tempValue;




                        if (LblSalesID.Text.ToString() != "")
                        {
                            Sales FindTestName = new Sales();
                            string SalesPerosnFullname = FindTestName.SalesPersonName(LblSalesID.Text.ToString(), LblCountry.Text.ToString());


                            if (UserLoginType() == 1 || UserLoginType() == 3)
                            {

                                UserLogin_Properties();
                                Sales cl_SalesPersons = new Sales();

                                DataTable tbSalesPerson = cl_SalesPersons.ConvertListToDataTable(cl_SalesPersons.FillAllSalesPerson(LblCountry.Text.ToString()));
                                DropDownTest.DataSource = tbSalesPerson;

                                DropDownTest.DataTextField = "Column1";
                                DropDownTest.DataValueField = "Column1";
                                DropDownTest.DataBind();

                                DropDownTest.SelectedValue = SalesPerosnFullname;
                                Populate_DashBoard(1);

                            }
                            if (UserLoginType() == 2)
                            {

                                UserLogin_Properties();
                                Populate_DashBoard(2);
                            }
                        }


                    }


                    //=================================================================================================

                   



                }//end of Ispost 

            }
            catch (Exception PageErr)
            {
                string ErrMessage="";
              
                ErrMessage ="Page Load -"+PageErr.Message.ToString()+"Source -"+ PageErr.Source.ToString() +"StackTrace -"+ PageErr.StackTrace.ToString();
              
            
            }

        }

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Hope someone can show me where is the error or how to find the where is