var x = 0;

function rotate(num){
x=num%document.slideForm.slide.length;
if(x<0){x=document.slideForm.slide.length-1};
document.images.indicadores.src=document.slideForm.slide.options[x].value;
document.slideForm.slide.selectedIndex=x;
}

function apRotate() {
if(document.slideForm.slidebutton.value == "Parar"){
rotate(++x);window.setTimeout("apRotate()", 10000);}
}