var my_width;
var my_height;
	
function getSizes(){
	
	var images = document.getElementsByTagName("img");

	for( var i=0; i < images.length; i++){
		
	if (images[i].className == "small_photo"){
		images[i].onclick=function(){openPreview(this.src);};
	}
	
}

	
	
}

function openPreview(image_url){
	var preview = document.getElementById("preview");
	
	var image = preview.getElementsByTagName('img');
	
	image[1].src = image_url.replace(/sm/,"lg");

	preview.style.display = 'block';
	
	
}

function closePreview(id){
	var preview = document.getElementById(id);
	
	var image = preview.getElementsByTagName('img');
	
	image[1].src = "";
	
	preview.style.display = 'none';
}


function changeParent(parentId){
	document.getElementById(parentId).className = "nav_hover";	
	
}

function changeParentBack(parentId){
	document.getElementById(parentId).className = "";	
}