function changeColour(elementId) {
	var interval = 1000;
	var colour1 = "#ff0000"
		var colour2 = "#000000";
	if (document.getElementById) {
		var element = document.getElementById(elementId);
		element.style.color = (element.style.color == colour1) ? colour2 : colour1;
		setTimeout("changeColour('" + elementId + "')", interval);
	}
}