if (res != NS_OK) {  delete inst; }
NS_RELEASE(inst);
nsresult nsWidgetFactory::CreateInstance(nsISupports *aOuter,                                            const nsIID &aIID,                                            void **aResult)  {      if (aResult == NULL) {          return NS_ERROR_NULL_POINTER;      }      *aResult = NULL;      if (nsnull != aOuter) {        return NS_ERROR_NO_AGGREGATION;    }    nsISupports *inst = nsnull;    if (mClassID.Equals(kCWindow)) {        inst = (nsISupports*)new nsMacWindow();    }    else if (mClassID.Equals(kCPopUp)) {        inst = (nsISupports*)new nsMacWindow();    }    else if (mClassID.Equals(kCChild)) {        inst = (nsISupports*)new ChildWindow();    }    else if (mClassID.Equals(kCButton)) {        inst = (nsISupports*)(nsWindow*)new nsButton();    }    else if (mClassID.Equals(kCCheckButton)) {        inst = (nsISupports*)(nsWindow*)new nsCheckButton();    }    else if (mClassID.Equals(kCCombobox)) {        inst = (nsISupports*)(nsWindow*)new nsComboBox();    }    else if (mClassID.Equals(kCRadioButton)) {        inst = (nsISupports*)(nsWindow*)new nsRadioButton();    }    else if (mClassID.Equals(kCFileOpen)) {       inst = (nsISupports*)(nsWindow*)new nsFileWidget();    }    else if (mClassID.Equals(kCListbox)) {       inst = (nsISupports*)(nsWindow*)new nsListBox();    }    else if (mClassID.Equals(kCHorzScrollbar)) {        inst = (nsISupports*)(nsWindow*)new nsScrollbar(PR_FALSE);    }    else if (mClassID.Equals(kCVertScrollbar)) {        inst = (nsISupports*)(nsWindow*)new nsScrollbar(PR_TRUE);    }    else if (mClassID.Equals(kCTextArea)) {        inst = (nsISupports*)(nsWindow*)new nsTextAreaWidget();    }    else if (mClassID.Equals(kCTextField)) {        inst = (nsISupports*)(nsWindow*)new nsTextWidget();    }    else if (mClassID.Equals(kCAppShell)) {        inst = (nsISupports*)new nsAppShell();    }    else if (mClassID.Equals(kCToolkit)) {        inst = (nsISupports*)new nsToolkit();    }    else if (mClassID.Equals(kCLookAndFeel)) {        inst = (nsISupports*)new nsLookAndFeel();    }    else if (mClassID.Equals(kCLabel)) {        inst = (nsISupports*)(nsWindow*)new nsLabel();    }    else if (mClassID.Equals(kCMenuBar)) {        inst = (nsISupports*)(nsIMenuBar*) new nsMenuBar();    }    else if (mClassID.Equals(kCMenu)) {        inst = (nsISupports*)(nsIMenu*) new nsMenu();    }    else if (mClassID.Equals(kCMenuItem)) {        inst = (nsISupports*)(nsIMenuItem*) new nsMenuItem();    }    else if (mClassID.Equals(kCContextMenu)) {        inst = (nsISupports*)(nsIContextMenu*) new nsContextMenu();    }    else if (mClassID.Equals(kCPopUpMenu)) { //       inst = (nsISupports*)new nsPopUpMenu();					NS_NOTYETIMPLEMENTED("nsPopUpMenu");    }    else if (mClassID.Equals(kCSound)) {    	nsISound* aSound = nsnull;    	NS_NewSound(&aSound);        inst = (nsISupports*) aSound;    }    else if (mClassID.Equals(kCFileSpecWithUI))    	inst = (nsISupports*) (nsIFileSpecWithUI *) new nsFileSpecWithUIImpl;    else if (mClassID.Equals(kCTransferable))        inst = (nsISupports*)new nsTransferable();    else if (mClassID.Equals(kCXIFFormatConverter))        inst = (nsISupports*)new nsXIFFormatConverter();    else if (mClassID.Equals(kCClipboard))        inst = (nsISupports*)new nsClipboard();    else if (mClassID.Equals(kCDragService))        inst = (nsISupports*)NS_STATIC_CAST(nsIDragService*, new nsDragService());      if (inst == NULL) {          return NS_ERROR_OUT_OF_MEMORY;      }      nsresult res = inst->QueryInterface(aIID, aResult);    if (res != NS_OK) {          // We didn't get the right interface, so clean up          delete inst;      }    return res;  }  