function doHighlight(img)
{
    img.src = img.src.replace('-off', '-on');
}

function undoHighlight(img)
{
    img.src = img.src.replace('-on', '-off');
}

function getUrlVariable(variableName)
{
	var url = window.location.href;
	
	if(url.indexOf(variableName) < 1)
		return '';
	if(url.indexOf('?') < 1)
		return '';
	if(url.indexOf('=') < 1)
		return '';
		
	var location = url.split('?')[0];
	var variables = url.split('?')[1];
	if(variables.indexOf('&') < 1)
		return variables.split('=')[1];

	var varObjects = variables.split('&');
	for(var i=0;i<varObjects.length;i++)
	{
		var varObject = varObjects[i].split('=');
		if(varObject[0].toLowerCase() == variableName.toLowerCase())
			return varObject[1];
	}

    return '';
}