Strange actionscript problem: BUG?

I have a very strange “thing”, bug, problem - whatever.
I think my script is okay but flash doesn’t like it:

if (((Math.abs(this.eFX-this.eTX) + Math.abs(this.eFY-this.eTY)) <= 1) {
        this._x = this.eTX;
	this._y = this.eTY;
	delete this.onEnterFrame;
}

Flash gave me this error-message:

**Error** Symbol=Gallery, layer=Actions, frame=1:Line 190: ')' expected
     				if (((Math.abs(this.eFX-this.eTX) + Math.abs(this.eFY-this.eTY)) <= 1) {

Total ActionScript Errors: 1 	 Reported Errors: 1

What’s the problem with my script?