Adding MC's to 2D Array

I’m utilizing this code for a photo gallery, and I’m having issues with adding movie clips to arrays. This code compiles with an error stating “Label must be a simple identifier.”


//Encapsulating mc for thumbnail images.
var mcMaster = new MovieClip(); 
//Nested mc array for storing thumbnails
var mcThumb:Array = new Array();
var i, j;
for(i=1; i<=7; i++)
{ mcThumb*=new Array(); 
}
//Loop x and y in for loops. x=j, y=i. 
for(i=1;i<=7;i++)
{
	for(j=1;j<=3;j++)
	{
		mcThumb*[j]:MovieClip = new MovieClip(); //Error.  
		mcMaster.addChild(mcThumb*[j]);
	}
}
stop();

Any ideas?