function set_searchstring_placeholder() {
	searchNodes = document.getElementsByName('searchstring');
	searchField = searchNodes[0];
	if (! searchField.value) {
		searchField.value = "Zoeken...";
		searchField.style.color = '#999';
	}
}

function remove_searchstring_placeholder() {
	searchNodes = document.getElementsByName('searchstring');
	searchField = searchNodes[0];
	if (searchField.value=="Zoeken...") {
		searchField.value = '';
		searchField.style.color = '#000';
	}
}