var which_img_big = 1;
var max_img_big = 1;

function show_img_big(which_img_big, max_img_big) {	
	for (var i = 1; i <= max_img_big; i++) {
		document.getElementById('img_big_' + i).style.display = 'none'; 
	}
	document.getElementById("img_big_" + which_img_big).style.display = 'block'; 	
}

function hide_img_big(max_img_big) {
	for (var i = 1; i <= max_img_big; i++) {
		document.getElementById('img_big_' + i).style.display = 'none'; 
	}		
}