"Yobj# = Get Ground Height(1,x#,z#)"
There's ya problem "dude".
You are telling it to get the ground height of the first matrix, thus, everytime you call that, it will position the character ( on the Y axis ) at the height of the first matrix.
To change it, you need some sort of variable defining what matrix ( level ) you are on.
So, if you were on level 1, levelnum = 1, if you were on level 2, levelnum = 2 etc.
Then, you use that variable to get the height of the matrix you're currently on.
Yobj# = Get Ground Height(levelnum,x#,z#)
Hope I Helped...

Team EOD :: Programmer/Logical Engineer/All-Round Nice Guy