function showTab(index){
	var tempId = document.getElementById(index);
	var leftImg = document.getElementById(index+"L");
	var rightImg = document.getElementById(index+"R");
	
	tempId.className= "navOn";
	leftImg.src="images/nav_onL.jpg";
	rightImg.src="images/nav_onR.jpg";
	
}

function hideTab(index){
	var tempId = document.getElementById(index);
	var leftImg = document.getElementById(index+"L");
	var rightImg = document.getElementById(index+"R");
	
	tempId.className= "navOff";
	leftImg.src="images/nav_offL.jpg";
	rightImg.src="images/nav_offR.jpg";
	
}