How to tile follow cursor?

I want this white isometric tile to "snap" to the the background tile that the mouse is currently overlapping.

<img src="http://dl.dropbox.com/u/1024727/caps/tile1.PNG" border="0">

Here is my current code:

<img src="http://dl.dropbox.com/u/1024727/caps/tile2.PNG" border="0">

Which is obviously incorrect, since it will avoid the "inbetween" darker tiles. I tried comparing to see if "int(mouseX/23.5)" was an odd or even number then to position it accordinly, but that didn't work.

Here is a .cap file

Anyone have any ideas?

http://dl.dropbox.com/u/1013446/tilethingy.cap

Try looking at it like this.

Your grid is basically a bunch of squares, and from your tile you can find a small square, and a larger square.

<img src="http://dl.dropbox.com/u/666516/tile45.png" border="0" />

Try using the size of one of those to figure your coordinates.

Wow fantastic help, thanks a lot! :D

no prob, btw, I think there's a slight issue with mine, if you're moving your mouse diagonally down right, it favors the higher square

slight math error somewhere

lucid, its probably because the hotspot was at the top left. Just had to add +23.5 to the X/Y of the first half of the compare, and remove the -23.5 from the second half of the compare.

http://dl.dropbox.com/u/1024727/caps/tilethingy2.cap