function changeImage(elem){
	var parent = elem.parentNode.parentNode;
	var src = elem.src;
	var stringArray = new Array();
	var stringArray = src.split("/");
	var thumb_name = stringArray[stringArray.length-1];
	var name = thumb_name.substring(6);
	var bigest = name;
	name = 'medium_'+name;
	var url='';
	for(var i = 0; i<stringArray.length-1; i++){
		url = url+stringArray[i]+"/";
	}
	var browser=navigator.appName;
	if(browser=="Microsoft Internet Explorer"){
		parent.childNodes[0].childNodes[0].href='./uploads/'+bigest;
		parent.childNodes[0].childNodes[0].innerHTML = '<img src="'+url+name+'" alt="" />';
	}else{
		parent.childNodes[1].childNodes[1].href='./uploads/'+bigest;
		parent.childNodes[1].childNodes[1].innerHTML = '<img src="'+url+name+'" alt="" />';
	}
	
}