function hideImage(i){	
	var img = document.images[i];
	img.style.display = "none";
	}
	
function showImage(i){	
	var img = document.images[i];
	img.style.display = "block";
	}
	
	
	
function toggleImage( i_old, i_new ){

		hideImage(i_old);
		showImage(i_new);

}

function changeImage(newSrc, myName){
			document.images[myName].src = newSrc;
			
		}