function changePage(pageName){
    switch(pageName)
        {
        case "1":
          document.getElementById('main').src='news.html'
          break 
        case "2":
          document.getElementById('main').src='posters.html'
          break
		case "3":
          document.getElementById('main').src='links.html'
          break
		case "4":
          document.getElementById('main').src='contact.html'
          break
		case "5":
          document.getElementById('main').src='advertise.html'
          break
        default:
           alert("Sorry, Invalid Page Selection.")
        break
        }
}