Getting error message trying to prototype mouseOver

hello,

i’m stuck on a problem with prototyping mouseOver for MovieClip.

i’m trying to use mouseOver (so that i use onClipEvent(mouseMove) to display a larger image on top of 9 smaller images, then hide the larger image when user moves the mouse off the smaller image.

i can’t use the onClipEvent(mouseUp) and onClipEvent(mouseDown) because i’m using these for dragging the images around.

i need to solve this for my work, but i can’t get it to work.

the error message i get when i try to publish this is:

Error Scene=Scene 1, layer=main, frame=3:Line 194: Syntax error.
MovieClip.prototype.mouseOver() {

Total ActionScript Errors: 1 Reported Errors: 1

can anyone help please.