//al caricamento funzione ajax
xajax.callback.global.onRequest = function(){
			jQuery.blockUI({ 
				message: '<h1>Sto Caricando ...</h1>' ,
			    css: { 
        		border: 'none', 
        		padding: '15px', 
        		backgroundColor: '#000', '-webkit-border-radius': '10px','-moz-border-radius': '10px', 
        		opacity: '.5', 
        		color: '#fff' 
    					} }); 
			};
//a fine caricamento fuziona ajax
xajax.callback.global.onComplete = function(args){
			jQuery.unblockUI();
			}