window.onload = function(){
	logoImage = document.getElementById("logo").getElementsByTagName("img");
	if(logoImage.length!=0){
		objImage = new Image();
		objImage.onLoad = resizeLogo(logoImage[0]);
		objImage.src = logoImage[0].src;
	}
}

function resizeLogo(logoImage){
	var parent = logoImage.parentNode.parentNode;
	var parentHeight = parent.offsetHeight;
	var offset = logoImage.offsetHeight;
	if(offset < parentHeight){
		var marginTop = (parentHeight-offset)/2;
	}else{
		var marginTop = 0;
	}
	logoImage.style.marginTop = marginTop+'px';
	logoImage.style.visibility = 'visible';
}