Are you on the demo version? Looks like. Texture - go to color and select mapping instead of procedural color. Then a little square opens and there you can load your bitmap. Be aware that this is difficult here at Renderosity. Because of the no tolerance for warez copies thingie. Normally the "correct" answer is the manual page. Only the demo does not have a printed manual, therefore i assume you have that.

One day your ship comes in - but you're at the airport.