Popup window does not close when "OK" button is clicked in Reports Server CGI

A report is generated by Reports Server CGI with a URL input.   After the report is created, a pop-up window opens with "Report output was successfully written to requested destination".  This pop-up has an OK button, but it does not close the window because the HTML code says OnClick=history.back(), but there is no history.  How can I change this to OnClick=windows.close() so the window will close when the button is clicked?

This is the URL submitted to generate the report:

http://server_name:port/dev60cgi/rwcgi60?GQMAILKEY&report=GQQD.rdf&desformat=PDF&destype=FILE&desname=destination_path.pdf&P_QNUM=679878&P_UNQ_ID=16870&P_DRAFT=N