public DrawPanel( int width, int height, int cellx, int celly ) {
		this.width = width;
		this.height = height;
		this.cellx = cellx;
		this.celly = celly;
		this.grid = new int[cellx][celly];
		
		for( int i = 0; i < cellx; i++ ) {
			for( int j = 0; j < celly; j++ ) {
				grid[i][j] = 0xFFFFFF;
			}
		}
		
		setPreferredSize( new Dimension( width+1, height+1 ) );
		addMouseListener( this );
	}