public static string GencusID(TextBox txtcustomerid) { int iicount = 0; string ID = ""; db = new db_MiletecDataContext(); var query = db.sp_genCustomerID(); foreach (sp_genCustomerIDResult count in query) { //count customer registered in the database iicount = count.count.Value; //increment iicount = iicount++; } ++iicount; //substring from lengths 1-2, padleft 4-2 if (iicount.ToString().Length.Equals(1)) { ID = "CustomerID-" + iicount.ToString().PadLeft(4, '0').ToString(); } else if (iicount.ToString().Length.Equals(2)) { ID = "CustomerID-" + iicount.ToString().PadLeft(3, '0').ToString(); } else { ID = "CustomerID-" + iicount.ToString().PadLeft(2, '0').ToString(); } return(txtcustomerid.Text = ID); }