Parameters:PANEL* Panel pointer.
num Number of an existing button (1 = first button of the panel), or 0 for adding a new button to the panel.
type Type of the button, 1 = push, 2 = toggle, 3 = radio.
x, y, ... Button parameters to be set - see button.

Returns:
Number of the button, or 0 if the button could not be found or created.
Example:
BMAP* clicked_pcx = "clicked.pcx";
BMAP* over_pcx = "over.pcx";
BMAP* normal_pcx = "normal.pcx";

PANEL* main_pan = { bmap = "main.pcx"; flags = SHOW; }

function exit_program() { sys_exit(NULL); }

function main()
{
mouse_mode = 4; // activate mouse
pan_setbutton(main_pan,0,1, // set a new push button for quitting the game
150,130,clicked_pcx,normal_pcx,over_pcx,NULL,exit_program,NULL,NULL);
}