function banner(imgSource,chance) {
this.imgSource = imgSource;
this.chance = chance;
}
function dispBanner() {
with (this) document.write("<IMG SRC='" + imgSource + "' WIDTH=464 HEIGHT=177 BORDER=0>");
}
banner.prototype.dispBanner = dispBanner;
banners = new Array();

banners[0] = new banner("img/estrutura/h1_20.jpg",10);
banners[1] = new banner("img/estrutura/h2_20.jpg",10);
banners[2] = new banner("img/estrutura/h3_20.jpg",10);
banners[3] = new banner("img/estrutura/h4_20.jpg",10);
banners[4] = new banner("img/estrutura/h5_20.jpg",10);
banners[5] = new banner("img/estrutura/h6_20.jpg",10);
banners[6] = new banner("img/estrutura/h7_20.jpg",10);
banners[7] = new banner("img/estrutura/h8_20.jpg",10);
sum_of_all_chances = 0;
for (i = 0; i < banners.length; i++) {
sum_of_all_chances += banners[i].chance;
}
function randomBanner() {
chance_limit = 0;
randomly_selected_chance = Math.round((sum_of_all_chances - 1) * Math.random()) + 1;
for (i = 0; i < banners.length; i++) {
chance_limit += banners[i].chance;
if (randomly_selected_chance <= chance_limit) {
document.write("<IMG SRC='" + banners[i].imgSource + "' WIDTH=464 HEIGHT=177 BORDER=0>");
return banners[i];
break;
}
}
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}