var foto1 = new Image();
var foto2 = new Image();
var foto3 = new Image();

foto1.src = "/images/navigatie/kamer_spiegel.jpg";
foto2.src = "/images/navigatie/strand_relax.jpg";
foto3.src = "/images/navigatie/opdiek1.jpg";

function doButtons(picimage) {
eval("document['picture'].src = " + picimage + ".src");
}