Shell Programming and Scripting

Hi guys:

I've got this problem, I want to move a bunch of files to 3 different folders, without any specific order, and I'm trying to automatize it with a shell script.
I'm a newbie at shell scripting so this is my first try:

Code:

#!/bin/bash

COUNTER=`ls -1 | wc -l`

while [ "$COUNTER" != "0" ]
do
    ARRAY=( $(ls | head -n 3) ) 
    mv ${ARRAY[0]} folder1/
    mv ${ARRAY[1]} folder2/
    mv ${ARRAY[2]} folder3/
done

But I can't make it work. When executed it moves half of the files to folder1, the other half to folder2 and deletes folder3 (?). It also creates a folder called folder1 inside folder1, but it doesn't do that with folder2.
As you can see, I'm trying to do this by reading the first 3 files inside the folder where the script is executed and then putting them inside an array to make the 3 mv statements. I'm sure it's all messed up.
I'll really appreciate your help with this one.