BANNER_ID = 'banner';

function changeBanner(imgName)
{
	originalSrc = document.getElementById(BANNER_ID).getAttribute('src');
	startOfFileName = originalSrc.lastIndexOf('/');
	newSrc = originalSrc.substring(0,startOfFileName + 1);
	newSrc = newSrc + imgName;		
	document.getElementById(BANNER_ID).src = newSrc;
}

function restoreBanner()
{
	originalSrc = document.getElementById(BANNER_ID).src;
	startOfFileName = originalSrc.lastIndexOf('/');
	newSrc = originalSrc.substring(0,startOfFileName + 1);
	newSrc = newSrc + 'banner.png';	
	document.getElementById(BANNER_ID).src = newSrc;
}

function removeBackgroundImg(elementId)
{
	document.getElementById(elementId).style.backgroundImage = "none";
}