function MoveR(name, name_min, name2, name2_min) {      
          var xmlhttp = new ajax("ajax/moveright/");
          xmlhttp.method = "GET";
          xmlhttp.onCompletion = function(){
            if (this.response != \'failed\') {
                return true;
            } else { return false; }
          };          
          xmlhttp.runAJAX("photoname=" + escape(name) + "&photoname_min=" + escape(name_min) + "&photoname2=" + escape(name2) + "&photoname2_min=" + escape(name2_min));
  }

function MoveR(uchwyt) {      
// ...
          xmlhttp.onCompletion = function(){
uchwyt(parametry);
          };          
// ...
  }

MoveR(function(parametry){
alert(parametry);
});