Hieghtmap problem

My hieghtmap just changes into a flat plane when I run the program. Am I using the wrong function or something? Or am I just doomed to using the modifyterrain command forever? :/

The Code:

;The hieghtmap
dam=LoadTerrain( "C:/3dgame/dam_hmap.bmp" )
PositionEntity dam,0,-40,0
dam_tex=LoadTexture( "C:/3dgame/dam_tex.bmp" )
EntityTexture dam,dam_tex
TerrainDetail dam,4000

Try: ScaleEntity dam,1,100,1

D'oh!
I always forget that bit!
Thank you Fredborg!

So I guess you got that dam terrain working?