Close External Window in Web Dynpro Application

Hi Folks,

I am working on a development in Web Dynpro and I am pretty new to this topic, so I seek your help.

The scene is:

I have created a Web Dynpro application in which I open an URL using CREATE_EXTERNAL_WINDOW method of the Window Controller. I am able to open the window but not able to close it.

I tried using methods,

 CLOSE() 

and

  SET_CLOSE_IN_ANY_CASE() 

but no success.

Please guide me if anything more needs to be done for closing the opened window.

Thank you.

Sud.