This is a button:

PANEL (panel name)
{
...
BUTTON = x, y, bmapon, bmapoff, bmapover, actionon, actionoff, actionover
...
}

Descriptions:
x = The X position of button on the panel.
y = The Y position of button on the panel.
bmapon = This bitmap is visible when mouse CLICKS on the button. (LEFT CLICK)
bmapoff = Normal Bitmap.
bmapover = When the mouse pointer is OVER the button.
ActionOn = Will be executed when mouse CLICKS on the button.
ActionOff = Is executed when the mouse is HOLD on the button and after RELEASED.
ActionOver = Is executed when the mouse is OVER the button.

-GeorgeSolarD.