set this in your function:

dt_splash_bmp = bmap_createblack(500,45,32);
bmap_fill (dt_splash_bmp,vector(0,0,0),70);
PANEL* my_pan = pan_create ("bmap = dt_splash_bmp; red = 255; green = 0; blue = 0", 102);

dt_splash_bmap: I have problems if i create this pointer inside the function, so i create it outside:

BMAP* dt_splash_bmap;

Maybee another can help here...