Proper way of invoking API

[Simonkale]

Hi!
In some source codes, I have seen API used like this:
SendMessage(rtfText.hwnd, EM_GETMODIFY, 0&, 0&)


What is "&" doing here? I mean if I remove he "&" sign
code still works.
SendMessage(rtfText.hwnd, EM_GETMODIFY, 0, 0)


Is there any difference?