protected void OnRowDeleting(object sender, GridViewDeleteEventArgs e)
{
int iStock_id, iQunatity;
iStock_id = Convert.ToInt32(e.Values["STOCK_ID"]);
iQunatity = Convert.ToInt32(e.Values["QUANTITY"]);
int index = Convert.ToInt32(e.RowIndex);
DataTable dt = ViewState["SALE_TRANSACTION_TABLE"] as DataTable;
dt.Rows[index].Delete();
ViewState["SALE_TRANSACTION_TABLE"] = dt;
SaleStockTrans.DataSource = ViewState["SALE_TRANSACTION_TABLE"] as DataTable;
SaleStockTrans.DataBind();
stock.UpdateStockQuantityAfterDelete(iQunatity, iStock_id);
}