var idBanner = 1;
var contador = 8;
var maximo = 4;
function contaSegundos() {
    if(contador == 2){
        fade('divban'+(idBanner), 2);
    }
    if(contador == 1){
        document.getElementById('divban'+(1 + (idBanner%maximo))).style.display="block";
        fade('divban'+(1 + (idBanner%maximo)), 0.2);  
    }
    if(contador == 0) {
        document.getElementById('imgnavegaindex').src = 'imagens/slideindex/ban'+(1 + (idBanner%maximo))+'.gif';
        contador = 8; 
        if(idBanner == maximo)
            idBanner = 1;
        else
            idBanner = 1 + (idBanner%maximo);
        for(i = 1; i <= 4; i++){
            if(i != idBanner)
                document.getElementById('divban'+(i)).style.display="none";
        }
    }
    if (contador != 0){
        contador = contador-1;
        setTimeout("contaSegundos()", 1000);
    }
}
		
function trocaBanner(idBan){
    fade('divban'+(idBan), 0.2); 
    document.getElementById('divban'+idBan).style.display="block";
    document.getElementById('imgnavegaindex').src = 'imagens/slideindex/ban'+idBan+'.gif';
    contador = 8; 
    if(idBan == maximo)
        idBanner = 1;
    else
        idBanner = idBan;
    for(i = 1; i <= 4; i++){
        if(i != idBan){
            document.getElementById('divban'+(i)).style.display="none";
            fade('divban'+(i), 1);  
        }
    }
}
		
var TimeToFade = 2000.0;
function fade(eid, estado){
    var element = document.getElementById(eid);
    element.FadeState = estado;
    if(element == null)
        return;
		   
    if(element.FadeState == null){
        if(element.style.opacity == null || element.style.opacity == '' || element.style.opacity == '1'){
            element.FadeState = 2;
        }
        else{
            element.FadeState = -2;
        }
    }
		   
    if(element.FadeState == 1 || element.FadeState == -1){
        element.FadeState = element.FadeState == 1 ? -1 : 1;
        element.FadeTimeLeft = TimeToFade - element.FadeTimeLeft;
    }
    else{
        element.FadeState = element.FadeState == 2 ? -1 : 1;
        element.FadeTimeLeft = TimeToFade;
        setTimeout("animateFade(" + new Date().getTime() + ",'" + eid + "')", 33);
    }  
}
		
function animateFade(lastTick, eid){  
    var curTick = new Date().getTime();
    var elapsedTicks = curTick - lastTick;
		 
    var element = document.getElementById(eid);
		 
    if(element.FadeTimeLeft <= elapsedTicks){
        element.style.opacity = element.FadeState == 1 ? '1' : '0';
        element.style.filter = 'alpha(opacity = '
        + (element.FadeState == 1 ? '100' : '0') + ')';
        element.FadeState = element.FadeState == 1 ? 2 : -2;
        return;
    }
		 
    element.FadeTimeLeft -= elapsedTicks;
    var newOpVal = element.FadeTimeLeft/TimeToFade;
    if(element.FadeState == 1)
        newOpVal = 1 - newOpVal;
		
    element.style.opacity = newOpVal;
    element.style.filter = 'alpha(opacity = ' + (newOpVal*100) + ')';
		 
    setTimeout("animateFade(" + curTick + ",'" + eid + "')", 33);
}