/// generic functions

var loadingMessage;

showVC = function() {
	if (!loadingMessage) createLoadingMessage();
	loadingMessage.style.visibility = 'visible';	
}

hideVC = function() {
	loadingMessage.style.visibility = 'hidden';
}


createLoadingMessage = function() {
    loadingMessage = document.createElement('div');
    loadingMessage.setAttribute('id', 'loadingMessage');
    loadingMessage.style.position = "absolute";
    loadingMessage.style.zIndex = "1000";
    loadingMessage.style.left = "0px";
    loadingMessage.style.top = "0px";
    loadingMessage.style.width = "100%";
    loadingMessage.style.height = "100%";
    document.body.appendChild(loadingMessage);

    var messageZone = document.createElement('div');
    messageZone.setAttribute('id', 'messageZone');
    messageZone.style.position = "absolute";
    messageZone.style.top = "0px";
    messageZone.style.right = "0px";
    messageZone.style.background = "red";
    messageZone.style.color = "white";
    messageZone.style.fontFamily = "Verdana,Helvetica,Arial,sans-serif";
	messageZone.style.fontSize = "1.2em";
	messageZone.style.fontWeight = "bold";
    messageZone.style.padding = "6px";
    loadingMessage.appendChild(messageZone);

    var text = document.createTextNode('Loading...');
    messageZone.appendChild(text);

    loadingMessage.style.visibility = 'hidden';

}