Hittest problems (in movie clips)

heyall :deranged: i am having a few problems with my hitests see

onClipEvent (enterFrame) {
 if (this.hitTest(_root.blue_mc)) {
  _root.healthbar.gotoAndStop(_root.healthbar._currentframe -= 5);
 }
}

is giving me huge dramas this is the currant fla file what i want it to do is to: when w is pressed and glover_mc contacts… i cant esplain this… ummm… i need a simple hittest that when _root.this.red_mc hits _root.blue redhealth_mc -=2

if u know (ive looked thru forums and other work i just cant find it
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