Planning app hangs up

In the extension class of BPS Web Application, following coding has been written to download data at the Presentation layer (User-Terminal).

mr_response->set_data( "file_stream_var" ).
mr_response->set_header_field( name = 'Content-Type' value = "text/html" ).
mr_resposne->set_header_field( name = 'Content-Length' value = "file_stream_length_var" ).
mr_response->set_header_field( name = 'Content-Disposition' value = 'attachment; filename=myFileName.csv' ).
mr_resposne->delete_header_field( name = 'Cache-Control' ).
mr_response->delete_header_field( name = 'Expires' ).
mr_response->delete_header_field( name = 'Pragma' ).

mr_navigation->response_complete( ).

The DISPATCH Method is so programmed, that when a user clicks on download button (SAVE) it would execute this code.

<b>I am able to download the file. </b>

<i>

Problem: The Modal Box "Your request is being processed" dosen't gives control back to the Planning Web Application . It stays up there forever and the user could do nothing more.

</i>

Any experiences and suggestions would be appreciated.

Thanks