Simple if statement confusing me

Im trying to thumbnails in incremental order. There will be only 10 thumbs and 10 pictures that will be changed by the client. So I dont need any thing complicated. What I am trying is something like this.


onClipEvent(load){
this._visible=false;
this.thumbclip.loadMovie("thumb1.jpg");
}
onClipEvent(enterFrame){
if(this.thumbclip.getBytesLoaded==this.thumbclip.getBytesTotal){
this._visible=true
_parent.nextFrame();
delete this.onEnterFrame
}else{_parent.gotoAndStop(15);
}

If I take _parent.nextFrame(); it works, but then they all load at once, but if I leave it in the thumbs dont even show up. Its like the _mc trys another onEnterframe again and the code get obliverated.
And my delete this.onEnterFrame doesnt work if I trace it. it just keeps looping. What am I doing wrong?