Outlook 365 WEB ADDIN onMessageSend

Question

Hi Every one, I have developed an Outlook 365 Web Addin. This Addin saves email subject and body on send(Compose) email. This Addin has also a task pane, some parameter are selected from this task pane. Compose email and select some values from task pane , if send button clicked email sent and called an API to save subject and body along with some parameters from task pane. Now when send button is clicked a message shown "Addin for Outlook is working on your request " even if task pane is not open. I want Addin should not invoke/trigger if task pane is not open and "Addin for Outlook is working on your request " message should not displayed. Here is portion of manifest for onSendMessage <ExtensionPoint xsi:type="LaunchEvent"> <LaunchEvents>       <LaunchEvent Type="OnMessageSend" FunctionName="onMessageSendHandler" SendMode="SoftBlock"/>      </LaunchEvents>      <SourceLocation resid="WebViewRuntime"/>   </ExtensionPoint> and bind in UI-less json file Office.actions.associate("onMessageSendHandler", onItemSendHandler);