function GoNav(cid){
				 document.getElementById("sub_nav2").style.display="none";
				 document.getElementById("sub_nav3").style.display="none";
				 document.getElementById("sub_nav4").style.display="none";
				 document.getElementById("sub_nav5").style.display="none";
				 document.getElementById("sub_nav6").style.display="none";
				 document.getElementById("sub_nav7").style.display="none";
				 document.getElementById("sub_nav8").style.display="none";
				 document.getElementById("sub_nav9").style.display="none";
				 document.getElementById("sub_nav10").style.display="none";
				 document.getElementById(cid).style.display="block";
}