var pics = new Array();
pics.push({'pic':'http://s3.allesoverbesparen.nl.s3.amazonaws.com/nu/energievergelijken_072010.gif', 'url':'http://www.laagstehypotheekofferte.nl/campagnes/?u=11194'});

var number = Math.floor(Math.random()*(pics.length));
blok  = '<div style="margin-top:5px">';
blok += '<a href="'+pics[number].url+'" target="_blank"><img src="'+pics[number].pic+'" border="0" /></a>';
blok += '</div>';
document.writeln(blok);