var box;

document.observe('dom:loaded', function()
{
    box = $('fannounce');
    new Draggable(box,
    {
	onEnd: function()
	{
	    new Ajax.Request(base_url+'ajax/fannounce_reposition/'+parseInt(box.style.left)+'/'+parseInt(box.style.top));
	}
    });

    if(browser == 'Internet Explorer' && parseInt(version) == 6)
    {
	new PeriodicalExecuter(__compute_position,0.1);
    }
});

function __compute_position()
{
    var offsets = document.viewport.getScrollOffsets();
    var viewH = document.viewport.getHeight();
    var top = parseInt(box.getStyle('top'));
    var boxH = box.getHeight();

    box.setStyle('position: absolute;');

    if(top < offsets.top && boxH < viewH) box.setStyle('top: '+ (offsets.top + 5) + 'px');
    if((top + box.getHeight()) > (viewH + offsets.top) && top > 5 && boxH < viewH) box.setStyle('top: '+ (offsets.top - 10 + (viewH - boxH)) + 'px');
}