function resize() {
	var foot = document.getElementById('footer_wrap');
    var footHeight = foot.offsetHeight;
    foot.style.marginTop = -footHeight+"px";
    document.getElementById('main').style.paddingBottom = footHeight+"px";
    }

function switch_block(block_id) {
	var block = document.getElementById(block_id);
	if (block.style.display == "none")
		block.style.display = "block";
	else
		block.style.display = "none";
	}
     
    window.onload = resize;