function go(obj) {
	var s = document.getElementById(obj);
	var k = document.getElementById("nav_con").getElementsByTagName("p"); 	
	if(s.style.display != "block"){ 
		for (var i = 0; i < k.length; i++) { k[i].style.display = "none"; }
		s.style.display = "block";
		document.getElementById("nav_con").style.display = "block";
		document.getElementById("nav_con").onclick = function() {
			document.getElementById("nav_con").style.display = "none";
			s.style.display = "none";
		};
		document.getElementById("right").onclick = function() {
			document.getElementById("nav_con").style.display = "none";
			s.style.display = "none";
		};

	} else {
		s.style.display = "none";
		document.getElementById("nav_con").style.display = "none";
	}
}