Not moving to frame lable

Ok. I finally finsihed my first game but have one slight problem. The timeline refuses to move from frame 4 to frame 5 which contains text and a button which should takes you to frame 6. I don’t understand why this doesn’t happen as I’ve used the same code and method for frames 2-3.

This is the code I've used on frame 4:
stop();
    // initialise variables 
    bulletNum = 0;
    dropdown = false;
    speed = 15;
    _root.bombspeed = 0.1;
    initAliens("bug");
    //
 //	-----------		ONLOAD	-----------	//
    _root.onLoad = function() {
    	Mouse.hide();
    };
    //
 //	-------------	ENTERFRAME	----------	//
    _root.onEnterFrame = function() {
    	// move the defender with the mouse. 
    	_root.defender._x = _root._xmouse;
    	_root.defender._y = 385;
    	// bullet move
    	var y = 0;
    	while (y<6) {
    		eval("_root.bullet"+y)._y -= 30;
    		y++;
    	}
    	moveBombs("bug");
    	moveAliens("bug", 4,15);
    	initBombs(_root.bombspeed);
    };
    //
 //	-------------	MOUSE CLICK	----------	//
    _root.onMouseDown = function() {
    	// duplicate the bullet mc
    	attachMovie("bullet", "bullet"+bulletNum, bulletNum);
    	// set the coords to the mouse clik
    	eval("_root.bullet"+bulletNum)._x = _root.defender._x;
    	eval("_root.bullet"+bulletNum)._y = _root.defender._y;
    	// increment the bullet number
    	++bulletNum;
    	// if more than 5 bullets , start again at 0
    	if (bulletNum>5) {
    		bulletNum = 0;
    	}
    };
    
Frame 5 got a simple:
stop();
    stopAllSounds();
If anyone can help, I'd be most grateful. This is doing my 'ead in!:smirk:

Yossarian