How do I Slowly increase a background image..

How do I Slowly increase a background image as to give the illusion that you are falling towards it.

I was thinking like every 5 seconds +2 to width and height but I cant seem to get it right, with the expressions I mean.

Any help would be greatly appreciated!

I was playing around with text entry earlier and came up with this. You should be able to glean what you need from the code in the "Walk Away" or "Walk Here" section.

Here it is with just what you need:

Thank you for your reply I will check it out now

Thanks worked a treat, Im experimenting with the pov top down view and that's just what I needed it to look like so you get a good effect from the falling.