How to bind a second function to a button?

Question

css

Hi everybody!
Such a question, on the site there is a button to which the function of sending data to the mail is already attached (using js and php), how to attach the function of switching to another page to the same button, that is, roughly speaking, I filled out the necessary information, clicked, the info went to the mail, and the user opened the payment page.
thanks in advance!

Answer 1

Just write in the data sending function "if response from the server = success, then (and here register the transition to another page)

Answer 2

Write a redirect in the function where the data is sent. Show the code if you need more details