function MakeArray(n)
{
        this.length = n;
        for (var i = 1; i <= n; i++)
                {
                this[i] = 0
                }
        return this
}

originIMG = new MakeArray(8);
invertIMG = new MakeArray(8);

originIMG[2] = new Image( );
originIMG[3] = new Image( );
originIMG[4] = new Image( );
originIMG[5] = new Image( );
originIMG[6] = new Image( );
originIMG[7] = new Image( );

invertIMG[2] = new Image( );
invertIMG[3] = new Image( );
invertIMG[4] = new Image( );
invertIMG[5] = new Image( );
invertIMG[6] = new Image( );
invertIMG[7] = new Image( );

originIMG[2].src = "./intro_images/int_00.gif";
originIMG[3].src = "./intro_images/int_01.gif";
originIMG[4].src = "./intro_images/int_02.gif";
originIMG[5].src = "./intro_images/int_03.gif";
originIMG[6].src = "./intro_images/int_04.gif";
originIMG[7].src = "./intro_images/int_05.gif";

invertIMG[2].src = "./intro_images/int_00_i.gif";
invertIMG[3].src = "./intro_images/int_01_i.gif";
invertIMG[4].src = "./intro_images/int_02_i.gif";
invertIMG[5].src = "./intro_images/int_03_i.gif";
invertIMG[6].src = "./intro_images/int_04_i.gif";
invertIMG[7].src = "./intro_images/int_05_i.gif";

selected = null;
freezed = null;

function invertImageAt( index )
        {
        document.images[index].src = invertIMG[index].src;
        selected = index;
        status=document.images[index].name;
        }

function revertImage( )
        {
        if (selected != freezed)
                {
                document.images[selected].src = originIMG[selected].src;
                }
        return true;
        }

function freezeImage( index )
        {
        document.images[index].src = invertIMG[index].src;
        if (freezed != null)
                document.images[freezed].src = originIMG[freezed].src;
        freezed = index;
        selected = freezed;
        return true;
        }