function changeImage(prefix, id, row, column) {
	var image = document.getElementById(id);
	image.src = '<c:url value="/images/' + prefix + '_"/>out_r' + row + '_c' + column + '.jpg';
}
function changeImageBack(prefix, id, row, column) {
	var image = document.getElementById(id);
	image.src = '<c:url value="/images/' + prefix + '_"/>r' + row + '_c' + column + '.jpg';
}