function nav(a){
	var about = document.getElementById("about");
	var service = document.getElementById("service");
	var technology = document.getElementById("technology");
	var contact = document.getElementById("contact");
	var dotAbout = document.getElementById("dotAbout");
	var dotService = document.getElementById("dotService");
	var dotTechnology = document.getElementById("dotTechnology");
	var dotContact = document.getElementById("dotContact");
	if(a==1){about.style.display="block";about.style.zIndex="999";dotAbout.style.left="-181px";}
	if(a==2){about.style.display="none";dotAbout.style.left="-190px";}
	if(a==3){service.style.display="block";service.style.zIndex="999";dotService.style.left="-181px";}
	if(a==4){service.style.display="none";dotService.style.left="-190px";}
	if(a==5){technology.style.display="block";technology.style.zIndex="999";dotTechnology.style.left="-181px";}
	if(a==6){technology.style.display="none";dotTechnology.style.left="-190px";}
	if(a==7){contact.style.display="block";contact.style.zIndex="999";dotContact.style.left="-181px";}
	if(a==8){contact.style.display="none";dotContact.style.left="-190px";}
	}