Ramps, Inclines, and Ditches

I have been working on a movement script for a while now. on a flat surface my character moves smoothly.
i thought i was done but then i realized I had to test ramps. it was then that i realized that my movement script was far from over.

here is what i am trying to accomplish:
http://forum.nystic.com/download/file.php?id=8694the diagramRAmps.JPG (23.16 KiB) Not viewed yet

when you are on a ramp, i would like the character to move down the ramp if right is pressed, and up the ramp if right is pressed. i am trying to get rid of all bouncing. i would not like for the character to move in the direction of the gray areas.

Well my question is:

what kind of movement would to this the best?

i have been trying for a week now!! These things are so confusing; i am gonna go mad!! http://forum.nystic.com/images/smilies/icon_e_surprised.gif