function changeImage(el,pdf){
	$('main_img').src = el.href;
	$('view_model').href = pdf;
}
function toggleBox(id,el){
	var element = document.getElementById(id);
	if(element.style.display == 'none'){
		element.style.display = 'block';
		el.style.backgroundImage = "url(assets/images/arrow_down.png)";
	}else{
		element.style.display = 'none';
		el.style.backgroundImage = "url(assets/images/arrow.png)";
	}
}