function swap( i ) {
	switch ( i ) {
		case 1 :
			if ( flag1 ) {
				flag1 = false;
		        document.images[ 4 ].src = images[0].src;
				document.images[ 6 ].src = images[5].src;
			}
			else {
				flag1 = true;
				flag2 = false;
				flag3 = false;
				document.images[ 4 ].src = images[1].src;
				document.images[ 6 ].src = images[4].src;
			    document.images[ 7 ].src = images[6].src;
				document.images[ 8 ].src = images[7].src;
			}
			break;
		case 2 :
			if ( flag2 ) {
				flag2 = false;
				document.images[ 4 ].src = images[0].src;
				document.images[ 7 ].src = images[6].src;
			}
			else {
				flag2 = true;
				flag1 = false;
				flag3 = false;
				document.images[ 4 ].src = images[2].src;
				document.images[ 7 ].src = images[4].src;
				document.images[ 6 ].src = images[5].src;
				document.images[ 8 ].src = images[7].src;
							}
			break;
		case 3 :
			if ( flag3 ) {
				flag3 = false;
				document.images[ 4 ].src = images[0].src;
				document.images[ 8 ].src = images[7].src;
			}
			else {
				flag3 = true;
				flag1 = false;
				flag2 = false;
				document.images[ 4 ].src = images[3].src;
				document.images[ 8 ].src = images[4].src;
				document.images[ 6 ].src = images[5].src;
				document.images[ 7 ].src = images[6].src;
			}
			break;
	
	}
}