function gotoURL(url, div){
    new Ajax.Updater (
		      {success: div},
		      url,
		      {method: 'get', 
			      parameters: ''}
		      );
    setVisible($('go_home'), true);
}

function goHome(){
    gotoURL('home.php','content');
    setVisible($('go_home'), false);
}

function setVisible(element, bool){
    hidden = 'visible';
    if(!bool){
	hidden = 'visible';
    }
    element.style.visibility = hidden;
}