var max = 4;
var nrImages = 4;
function makeImages() {
this[0] = "http://i40.tinypic.com/2whqoog.jpg";
this[1] = "http://i43.tinypic.com/34io1ld.jpg";
this[2] = "http://i40.tinypic.com/25r37s3.jpg";
this[3] = "http://i41.tinypic.com/352505t.jpg";



this.length = nrImages;
}

function makeLinks() {
this[0] = "http://compare.buscape.com.br/visualiza?id=93&prod_id=69776318&emp_id=77&pos=9&az=13e288ca92362ebc76dcc4bbad4acc66&cn=45547517&nc=1741202013020091020132122&site_origem=9637271";
this[1] = "http://compare.buscape.com.br/visualiza?id=77&prod_id=62229086&emp_id=55206&pos=2&az=f1553ee34e92af1c9d9d70199c45796b&cn=45670110&nc=1741202013020091020132216&site_origem=9637271";
this[2] = "http://compare.buscape.com.br/visualiza?id=77&prod_id=59286285&emp_id=155&pos=14&az=1626b73ebbaa6e3f73fbda87ec9540b3&cn=45670110&nc=1741202013020091020132216&site_origem=9637271";
this[3] = "http://compare.buscape.com.br/visualiza?id=77&prod_id=63945205&emp_id=370&pos=28&az=d6b3ad06c7eaeb10edce37c80c02fccd&cn=45670110&nc=1741202013020091020132216&site_origem=9637271";




this.length = nrImages;
}


var vetImages = new makeImages();
var vetLinks = new makeLinks();
var x = Math.round(Math.random()*max);
var y = max / nrImages;
for(var cont = 1;cont*y<= max;cont++) {
if (x <= (cont*y)) {
document.write("<a href="+vetLinks[cont-1]+" target=_blank><img src="+vetImages[cont-1]+" border=0></a>");
break;
}
}