var openDesc = null;

function showDesc( id )
{
	var box = document.getElementById( id );
	var wrapper = document.getElementById( 'wrapper' );

	if( openDesc == null && box != null )
	{
		box.style.display = "block";
		wrapper.style.opacity = '0.5';
		wrapper.style.filer = "alpha( opacity=50 )";
		openDesc = box;
	}
	else if( openDesc == box )
	{
		box.style.display = "none";
		wrapper.style.opacity = '1';
		wrapper.style.filer = "alpha( opacity=100 )";
		openDesc = null;	
	}
	else
	{
		openDesc.style.display = "none";
		box.style.display = "block";
		openDesc = box;
	}
}