MAX  = 3;
  url  = new Array(MAX);
  img  = new Array(MAX);

	url[0]="purificadores.asp"
    img[0]="imagens/dest_p125.jpg"
	
	url[1]="purificadores.asp"
    img[1]="imagens/dest_megga.jpg"
	
	url[2]="maxclick.asp"
    img[2]="imagens/dest_maxclick.jpg"
	
  var now = new Date()

  var nro = (now.getSeconds() % MAX)
  document.write('<a href="'+url[nro]+'"><img src="'+img[nro]+'" border=0 align=absmiddle></a>')