function enable ( elem )
	{
		elem.removeAttr ( "disabled" );
	}
	
	function disable ( elem )
	{
		elem.attr ( "disabled", "disabled" );
	}
    
    $(document).ready(function() 
        {
            $('img.logo').click ( function ()
                {
                    window.location = '/main/index';
                });
        });