On Ok click button need info yes no Box using x++in d365fo

Hi,

I have to add an info box on the vendor Payment Proposal, before create Payment i need an info box where some static value show with selected invoices Amount (sum of specTrans.Balance01), on the click on Yes in the info box, payment will be created as per standard, but if we click on No button on the info box, it stays as same screen of Proposal.

Can anyone please suggest me that which blog i need to prefer and how can i solve it using x++ in D365fo?