Inrement problem, teach me lesson please

hello there,
i have a problem with making of flash photo gallery. using flash mx 2004.
i have a four frames, on my first frame i have this :

amount = 0;

on my second frame i have this :

 function clearThumbs()
{
	delAmount = 100;
	delNum = 1;
	while (delAmount > 0)
	{
		removeMovieClip("mc" + delNum);
		delNum++;
		delAmount--;
	}
 // while ends at this point
} 
// private function clear thumbs ends here
loop = 10;
mcX = 10;
i = amount + 1;
while (loop > 0)
{
	duplicateMovieClip(_root.thumb, "mc" + i, i);
	if (loop > 5)
	{
		setProperty("mc" + i, _x, mcX);
		setProperty("mc" + i, _y, 10);
	}
	else
	{
		setProperty("mc" + i, _x, mcX - 250);
		setProperty("mc" + i, _y, 60);
	} 
// its ends here
	this.imagNum["mc" + i + ".imageNum"] = i;
 
	i++;
	loop--;
	mcX = mcX + 50;
} 
// while ends at this point
if (amount <= 0)
{
	_root.prev._visible = false;
}
else
{
	_root.prev._visible = true;
} 
// if ends at this point
if (amount >= 30)
{
	_root.next._visible = false;
}
else
{
	_root.next._visible = true;
} 
// end if
 

on my third frame i have this :

 
// how many thumbs
picAmount = 10;
picNum = 0;
// increment 
picNum = picNum + amount;
while (picAmount >= 0)
{
// put the thumbs x, y
	loadMovie("thumbs/picture" + picNum + ".jpg", "mc" + picNum + ".thumbHold");
	picNum++;
 trace (picNum);
	picAmount--;
} 
// end here
if (picAmount = 1)
{
// load first picture in movie clip _root.square.stage, 
	first = picNum -10 ;
	loadMovie("big/picture" + this.first + ".jpg", _root.square.stage);
} 
// end 
stop();
 

fourth frame, has stop action.

I have a movie clip with instance name, thumbs…
problem starts here.
it wont load picture in the movie clip _root.square.stage

it has this AS in it :


 
onClipEvent (load)
{
	_alpha = 99;
}
on (rollOver)
{
	_alpha = 50;
}
on (rollOut)
{
	_alpha = 99;
}
on (release)
{
 _root.slideShow.temp = this.imageNum;
	_root.square.gotoandplay(1);
   // loadMovie("big/picture" + this.imageNum + ".jpg", _root.square.stage);
 loadMovie("big/picture" +imageNum + ".jpg",  _root.square.stage);
 trace(imageNum);
}

It gives me an error, cant load picture.jpg. Which is very wrong, there is no picture titled like this. You probably guessed from code that i have thumbs and big pictures.

Thumbs are loaded “thumbs/picture” from this directory.Big pictures are loaded from this directory “big/picture”. Thumbs are loaded, first picture is loaded.

How can i do it so when you clikc certain thumbs big picture is loaded in to the moveclip “_root.square.stage” ?

What do i do wrong ? Is there a better way for this gallery.
I know there are some nice free galleries, components and stuff. I want my own.

Please help,
Thank you all in advance,

p.s.
sorry for broken english