$sql = "UPDATE ".TB_PREF."stock_master SET material_cost=".db_escape($material_cost).",
labour_cost=".db_escape($labour_cost).",
overhead_cost=".db_escape($overhead_cost).",
$sql = "UPDATE ".TB_PREF."stock_master SET material_cost=".db_escape($material_cost).",
labour_cost=".db_escape($labour_cost).",
overhead_cost=".db_escape($overhead_cost).",