function updateBack(enable) {
    if (enable)
		document.getElementById("back").classList.remove("disabled");
	else
		document.getElementById("back").classList.add("disabled");
}

function updateForward(enable) {
    if (enable)
		document.getElementById("forward").classList.remove("disabled");
	else
		document.getElementById("forward").classList.add("disabled");
}

function updateLoading(is_loading) {
    if (is_loading) {
		document.getElementById("refresh").style.display = "none";
		document.getElementById("stop").style.display = "inline-block";
	} else {
		document.getElementById("refresh").style.display = "inline-block";
		document.getElementById("stop").style.display = "none";
	}
}

function updateURL(url) {
	document.getElementById('address').value = url;
}