nothing is wrong(or so it SEEMS!).
please copy and paste this,and make the error
GLOW// --------------------------------- //
// Project: triangleman
// Start: Saturday, October 03, 2009
// IDE Version: 7.082
// DEMO-VERSION:
// Missing features:
// No time limit during gameplay
// No watermark in executables
// SETCURRENTDIR("Media") // seperate media and binaries?
LOADBMP:"bigor.bmp"
LOADSPRITE:"triangle man shoot1.bmp" 0
LOADSPRITE:"tid.bmp" 1
LOADSPRITE:"slinger.bmp" 2
slinger_x=490
WHILE TRUE:animation
delta=delta+1
IF delta>15
ani=1-ani
delta=0
IF KEY(54)AND shooting=FALSE
shooting=TRUE
slinger_x=slinger_x-1
ENDIF
ROTOSPRITE:slinger_x,400,slinger_x*4
ENDIF sprite:ani, 315, 400
SHOWSCREEN WEND

thanks!(to replyers)[if you speak dutch,translate to english!]