t = '<a href="http://pp.kupujemy.pl/stats/click_ad/0flt?redir=http://www.kupujemy.pl/exz75-cena-sklep.html?from=0flt">Kup ten produkt</a>';

function AdboxRemovekupujemy_prodadbox_1(node)
{
		var len = node.childNodes.length;
		while (node.hasChildNodes())
		{
				node.removeChild(node.firstChild);
		}
}
pelement = document.createElement('div');
pelement.innerHTML = t;
AdboxRemovekupujemy_prodadbox_1(document.getElementById('kupujemy_prodadbox_1'));
document.getElementById('kupujemy_prodadbox_1').appendChild(pelement);