public static void FillDropDownListCustomerID(DropDownList ddl, SqlInt32 UserID)
{
CustomerBAL balCustomer = new CustomerBAL();
ddl.DataSource = balCustomer.SelectDropDownList(UserID);
ddl.DataTextField = "CustomerName";
ddl.DataValueField = "CustomerID";
ddl.DataBind();
ddl.Items.Insert(0, new ListItem("---Select Customer---", "-99"));
}