Event.observe(window, 'load', function(){
  $$('.tooltip').each(function(element){
  		element.setStyle({'cursor' : 'pointer'});
    	new Tip(element, element.select('span.tooltip_text')[0].innerHTML,
    	{
		    effect: false,
		    fixed: false,
		    hook: false,
		    showOn: 'mousemove',
		    title: false,
		    viewport: true
		  }
    	);
  });
});