How To Get The Top,Bottom,Left And Right Of The Screen?

Title...

The coordinates?
You can use screen.width and screen.height to get them, they give you the overall width&height of the screen.
To get the X/Y coordinate range just divide those values by 2 (since the origin is in the center).

xmax =  screen.width/2
xmin = -xmax
ymax =  screen.height/2
ymin = -ymin

That implies everything is at default and the origin has not been changed with screen.setTranslation( tx, ty )
Then you have to adjust accordingly to the situation.

Live Long And Tinker

ok tnx :D