flag = 0;
if (document.images)
{
	img01 = new Image();
	img01.src = "imagens/img01_on.gif";
	img02 = new Image();
	img02.src = "imagens/img02_on.gif";
	img03 = new Image();
	img03.src = "imagens/img03_on.gif";
	img04 = new Image();
	img04.src = "imagens/img04_on.gif";
	img05 = new Image();
	img05.src = "imagens/img05_on.gif";
	img06 = new Image();
	img06.src = "imagens/img06_on.gif";
	img07 = new Image();
	img07.src = "imagens/img07_on.gif";
	flag = 1;
}

function on(a)
{
  if (flag == 1){
    document.images[a].src="imagens/"+a+"_on.gif";
  }
}

function off(a)
{
  if (flag == 1){
    document.images[a].src="imagens/"+a+"_off.gif";
  }
}