How do I hide a GWT PopupPanel with a clickhandler?

I am trying to make the submit button on my PopupPanel hide the panel, but I cannot seem to get it to function properly. I am able to have a button on my entrypoint show the panel, but I cannot seem to get the PopupPanel to hide.

submitLinkPopup.btnSubmitLink.addClickHandler(new ClickHandler() {
    public void onClick(ClickEvent event) {
        if(if conditions go here){
        CallbackMethods.addLink(callback conditions go here);
                    //this is where I want to hide the panel
        }
        else{
          开发者_开发问答  Window.alert("Error: Fields cannot be empty");
        }

    }
});

popPanel.hide()