function posicio(){
if(navigator.appName=="Microsoft Internet Explorer"){
var mida=document.documentElement.offsetWidth;
var alt=document.documentElement.offsetHeight;

var pos=mida/2+60;
var pos2=alt/2-120;

document.getElementById('prod1').style.left=pos;
document.getElementById('prod1').style.top=pos2;
document.getElementById('prod2').style.left=pos;
document.getElementById('prod2').style.top=pos2;
document.getElementById('prod3').style.left=pos;
document.getElementById('prod3').style.top=pos2;
document.getElementById('prod4').style.left=pos;
document.getElementById('prod4').style.top=pos2;
document.getElementById('prod5').style.left=pos;
document.getElementById('prod5').style.top=pos2;
}
else{
var mida=document.documentElement.offsetWidth;
var alt=document.documentElement.offsetHeight;

var pos=mida/2+55;
var pos2=alt/2-134;

document.getElementById('prod1').style.left=pos;
document.getElementById('prod1').style.top=pos2;
document.getElementById('prod2').style.left=pos;
document.getElementById('prod2').style.top=pos2;
document.getElementById('prod3').style.left=pos;
document.getElementById('prod3').style.top=pos2;
document.getElementById('prod4').style.left=pos;
document.getElementById('prod4').style.top=pos2;
document.getElementById('prod5').style.left=pos;
document.getElementById('prod5').style.top=pos2;
}
}