function makeActive(tab) {
	el = document.getElementById(tab);
	
	el.style.backgroundImage= 'url(http://www.originalsignal.com/images/bg_tab6.gif)'; 
	el.style.height = '21px'; 
	el.style.marginTop = '-4px';
	el.style.paddingTop = '7px';
	
}

function hideActive(tab) {
	el = document.getElementById(tab);
	
	el.style.backgroundImage= ''; 
	
}


function showSub(id,subid) { 
	// id = de li tab
	// subid = onderliggende menu

	el = document.getElementById(subid);
	el.style.visibility = 'visible';
	
	tid = document.getElementById(id);
	tid.style.backgroundImage= 'url(http://www.originalsignal.com/images/bg_tab6.gif)'; 
	tid.style.height = '21px'; 
	tid.style.marginTop = '-4px';
	tid.style.paddingTop = '7px';
	
	//return false;
}

function hideSub(id,subid) { 
	// id = de li tab
	// subid = onderliggende menu
	
	el = document.getElementById(subid);
	el.style.visibility = 'hidden';
	
	tid = document.getElementById(id);
	tid.style.backgroundImage= ''; 
	
	//return false;
}