Targeting frame label within one MC from another MC?

[Jupiter09]

I'm creating a gallery for a client (We'll call him Joe Blow to protect his identity.) He's done several pieces of work for several different clients. I created separate movie clips for each client within a file called "PrintSample.fla". In this file, there are two movie clips for two clients - one named DrPepper_mc and the other named DMAmap_mc.

These MCs live on the main timeline, side by side.

View sample SWF file (http://thegamedame.com/etc/Sample.html)
Download PrintSample.fla (593KB) (http://thegamedame.com/etc/PrintSample.fla)

If you open DrPepper_mc, you'll see navigational buttons. These work beautifully. The last right arrow (located in Next under Frame Label "3") in DrPepper_mc is set to play frame 1 of the DMA stuff by using this code:
on (release) {
_root.nextFrame();
}

Awesome. So then, DMAmap_mc loads up. If you only click the right/next arrows, everything is great... but if a user is looking at the first sample piece within DMAmap_mc, (the scrolling one) and they click the left/previous arrow, it takes them to the first frame in DrPepper_mc. Here's the code used on that arrow now:
on (release) {
_root.prevFrame();
}


I don't want that left/previous arrow to take them to the first frame of DrPepper_mc. I want it to take them to the last section of DrPepper_mc. I've named the section I want to target within DrPepper_mc "3".

I tried using this code on that arrow:
on (release) {
_root.DrPepper_mc.gotoAndPlay("3");
}

And this:
on (release) {
_root.DrPepper_mc.gotoAndPlay(3);
}

But no luck. Please help if you can.

XOXO

[oldnewbie]

Check your Private Messages. I've sent you a link to a partly corrected .fla.