function dialog(){

  if (typeof dialog._initialized == "undefined") {
     
    dialog.prototype.build = function () { 
      var this_obj = this;
      //this.LOADING = new Loading("Loading Message, please wait...");
      //this.LOADING.modal = false;  
      this.obj = new YAHOO.widget.Dialog("popup_dialog",  
          			{ width:"540px", fixedcenter:true, constraintoviewport:true,
          			  draggable:false, zindex:400, modal:true, visible:false, underlay:"shadow"
          			 }); 
      this.obj.beforeShowEvent.subscribe(function() {
        //this_obj.LOADING.start();
      });
      this.obj.showEvent.subscribe(function() { 
        //this_obj.LOADING.destroyLoading();
      });		
    }
    
    
    dialog.prototype.close_button = function () {
      var hide = function(){ this.hide(); };
      ///////////////////////////////////////////////////////////////////////
      this.obj.cfg.setProperty("buttons", [ { text:"Close", handler:hide, isDefault:true } ]);
    }
    /////////////////////////////////////////////////////////////////////////////////////
    
    dialog._initialized = true;
  } 
}