Proper way to phrase an unload function -

below is my actionscript:

i’m having issues with my creative working differently in two different places. i think it has to do with the onrollout i have below:

function loadPix(pix){
pixHolder.loadMovie(pix);
}
button_1.onRollOver=function(){
//call the function, pass the specific picture name
loadPix(“http://www.whatever.com/test.jpg”);
}
button_1.onRollOut=function(){
loadPix("");
}

on roll over i want the image to load on the stage,
on roll out i want the pixholder to be empty.

is this the proper way to phrase the roll out?

}
button_1.onRollOut=function(){
loadPix("");
}

please help! it’s pretty urgent.

thank you!

jh.