Thanks Duffer.
I made the zoom box by using the sprite and stretch sprite command.
The image is first obtained by using a command like this:
get image 1,mousex()-20,mousey()-20,mousex()+20,mousey()+20
The value of the + or - is changed depending on the zoom level then the sprite is stretched to fill the zoom box. So for example if the zoom is set at 200% then the commands would look like this:
get image 1,mousex()-10,mousey()-10,mousex()+10,mousey()+10
stretch sprite 1,200
if the zoom is set at 400% then the commands would look like this:
get image 1,mousex()-5,mousey()-5,mousex()+5,mousey()+5
stretch sprite 1,400
Also you might not have figured this out yet but you can use the scroll button in the middle of the mouse to zoom in/out easier and if you click it you can toggle the crosshair on/off.
There are two types of people in this world: people who are extremly cool and are good at everything and people who are me.