I finally figured out how to achieve my goal. I was making a sunlight effect and it looks really good.
But due to it being a Gui it doesn't let me click on the screen for MouseDown() functions I have on other scripts.
PHP Code:
new GuiBitmapCtrl("SUN") {
x = 0;
y = 0;
width = screenwidth;
height = screenheight;
bitmap = "age_sun.png";
layer = 1;
}