Load external image

I have a flash file where a button loads a movie clip witht he following code:

on (rollover) {
this.attachMovie(“proj_1_1_mc”, “window”, 1);
window._x = 100;
window.y = 100;
unloadMovie("proj
");
}

How do i modify this so that the proj_1_1_mc movieclip loads an external image instead of putting it in the flash file and creating a movieclip symbol and thus bloating the file?

thx