ActionScript 3.0 :: Variable Losing/not Assigning Value?

I followed a dynamic gallery scrolling thumbs tutorial and then changed it quite a bit to fit my needs.

I basically added a previous and next button and image title box.

It all works great apart from one thing.

e.g. I click on thumb 5. I then use the next button and go to say... image15. I then click on thumb 9. When I use the prev or next button again it will resume from image15, but it should then carry on from thumb 9 as that was the last change I made.

I thought this would be as simple as assigning the thumb variable value to the image number variable. i.e myID = id; but it doesn't work. my variable myID actually loses its value when I click the thumb image (I used the trace to clarify).

Here is the code.

PHP Code:

function bttnClick(event:MouseEvent):void{
bttn.gotoAndStop(1);
root.logo.visible = false;
myID = id;

[Code].....