warning meaaage if supplier having invoice in same date

Hi Team,

User wants a notification or warning message while entering invoice if the supplier having invoice in same date.

I tried with form personalization.

Condition:-

exists(

select 'X'

from ap_Invoices_all

inv where ${Item.inv_sum_folder.invoice_id.value} is null

and inv.INVOICE_DATE=: INV_SUM_FOLDER.INVOICE_DATE

and inv.Vendor_id=${item.inv_sum_Folder.VENDOR_ID.Value})

Thanks in Advance,

Regards,

Ramesh