sub ReadBits
{
	my $BitStringIn = @_[0];
	my $OffsetRef	= @_[1];
	my $Length	= @_[2];
	my $ItemListRef	= @_[3];
	my $BitStringOut = 0;

	#capture the relevant bits
	$BitStringOut = substr($BitStringIn,$$OffsetRef,$Length);
	#update Offset
	$$OffsetRef += $Length;

	#determine the number of zero's I need to add to make a 32-bit number
	$NumZeros = 32-$Length;
	
	#Create string of zeros with a length of $NumZeros
	$Zeros = unpack("B$NumZeros",pack("N",0));
	
	#Insert string of zeros to $BitString to create a 32-bit string
	$BitStringOut = $Zeros.$BitStringOut;
	
	#Convert 32-bit string into a number
	$NumOut = unpack("N",pack("B32",$BitStringOut));
	
	#Update ItemList
	@$ItemListRef = (@$ItemListRef,$NumOut);
	return($NumOut);
}