var myimages = new Array();
function preloading()
{
	for (x=0; x<preloading.arguments.length; x++){
	myimages[x] = new Image();
	myimages[x].src = preloading.arguments[x];
	}
}
preloading("images/btn_o_firmie_over.jpg", "images/btn_nagrody_over.jpg", "images/btn_nasza_oferta_over.jpg", "images/btn_galeria_over.jpg", "images/btn_nasze_hobby_over.jpg", "images/btn_praca_over.jpg", "images/btn_kontakt_over.jpg");

function zmien(img)
{
	document.getElementById('fotka').src=img;
}