OverlayMessage = function ( container, top_position, container_w, container_h )
    {
    // Terminology:
    // +-----------------+
    // |wrapper          |
    // |+---------------+|
    // ||container      ||
    // ||   +-------+   ||
    // ||   |overlay|   ||
    // ||   +-------+   ||
    // ||               ||
    // |+---------------+|
    // +-----------------+
	
	if(!top_position) var top_position = '-200px';
	if(!container_w) var container_w = '80%';
	if(!container_h) var container_h = '200px';
	
    // Get the parent.
    var parent = container.parentNode;

    // Make the wrapper div.
    var wrapper = document.createElement( 'div' );
    wrapper.style.cssText = container.style.cssText;
    parent.insertBefore( wrapper, container );

    // Move the container into the wrapper.
    parent.removeChild( container );
    wrapper.appendChild( container );
    container.style.cssText = 'position: relative; width: '+container_w+'; height: '+container_h+';';

    // Add the overlay div.
    this.overlay = document.createElement( 'div' );
    wrapper.appendChild( this.overlay );
    this.visibleStyle = 'position: relative; top: '+top_position+'; background-color: #ffff00; width: 80%; height:30px; text-align: center; margin-left: auto; margin-right: auto; padding: 4px;  z-index: 100; opacity: .75; filter: alpha(opacity=75);';
    this.invisibleStyle = 'display: none;';
    this.overlay.style.cssText = this.invisibleStyle;
    };


OverlayMessage.backgroundColor = '#ffffff';
OverlayMessage.borderColor = '#006699';


OverlayMessage.prototype.Set = function ( message )
    {
    this.overlay.innerHTML = message;
    this.overlay.style.cssText = this.visibleStyle;
    };


OverlayMessage.prototype.Clear = function ()
    {
    this.overlay.style.cssText = this.invisibleStyle;
    };


OverlayMessage.SetBackgroundColor = function ( color )
    {
    OverlayMessage.backgroundColor = color;
    };


OverlayMessage.SetBorderColor = function ( color )
    {
    OverlayMessage.borderColor = color;
    };