function abrelink(URL) {

var width = 700;
var height = 500;

var left = 400;
var top = 50;

window.open(URL,'assinatura','width='+width+',height='+height+',top='+top+',left='+left+',scrollbars=yes,status=no,toolbar=no,location=no,directories=no,menubar=no,resizable=no,fullscreen=no');

}