total = 40;
today = new Date();
num = today.getTime();
num = (Math.round(Math.abs(Math.sin(num) * 1000000)) % total);

if (num >= 0 && num <= 10) {
	document.write('' +
	'<a href="./ecologizar.html"><img src="./img/banner.gif" width="468" height="60" border="0"></a> ' +
	'');
}
if (num >= 11 && num <= 20) {
	document.write('' +
	'<a href="./india.html"><img src="./img/banner1.gif" width="468" height="60" border="0"></a> ' +
	'');
}
if (num >= 21 && num <= 30) {
	document.write('' +
	'<a href="http://www.editorauniversa.ucb.br" target="_blank"><img src="./img/banner_universa.jpg" width="468" height="60" border="0"></a> ' +
	'');
}
if (num >= 31 && num <= 40) {
	document.write('' +
	'<a href="http://www.ecodesenvolvimento.org.br" target="_blank"><img src="./img/banner_ecodesenvolvimento.jpg" width="468" height="60" border="0"></a> ' +
	'');
}