How to display confirmation dialog box ?

@Rajginoya 

To invoke the dialog box from the code, you need to use the below code.

 Eg: ViewName.Ask()

Here is the article for your reference:

 https://asiablog.acumatica.com/2015/11/using-smart-panel.htmlsample

@Naveen Boga

This form does not just show a confirmation dialog box that you want to save the value or not

  protected void SOLine_RowUpdated(PXCache cache, PXRowUpdatedEventArgs e)
        {

            SOLine row = (SOLine)e.Row;
            SOLine oldrow = (SOLine)e.OldRow;
            foreach (SOLine soLine in Base.Transactions.Select())
            {
                if (soLine.BaseQty == Convert.ToDecimal(0))
                {
                    if (Base.Transactions.Ask("Transactions", PhoneRepairShop.Messages.BaseQtycheckzero, MessageButtons.OKCancel) == WebDialogResult.Cancel)
                    {
                        Base.Transactions.Current = oldrow;
                        return;
                    }
                }
            }

        }