change the tile url in the js file..

The resolution of regular map of australia is not good enough for me so
I made a php script that generate tile url the same way as google. I
just wonder where in the js script I can change
'http://mt.google.com/mt?v=w2.6&n=404&x=4598&y=6432&zoom=3' to
my-site?x=4598&y=6432&zoom=3 and then still be able to use the api with
zoom and pan and overlays? I still want to use the googles satelitte
tiles thou.
Cheers Kim