swf bitmap insertion

Hello, I'm trying to create a simple swf file including a bitmap... I use the following code : <? swf_openfile ("data/test.swf", 256, 256, 12, 0, 0, 0); swf_definebitmap (1, "test.jpg"); swf_placeobject(1, 50); swf_showframe(); swf_closefile (); ?> but, my bitmap doesn't appears in the movie.... I'm sure that I forgot to do a silly thing but don't know what. Does someone here have an Idea on what to do ? Thanks Regards Stef