Proper use of nohup within here-document?

[Mun]

Hi,

I'm using Bash version 4.1.2 on RedHat EL 6.8 (I realize these are old
releases).

In one of my bash scripts I have a here-document and at the end of
it's execution it will pop-up an gxmessage.  My problem is that when
the here-document exits, the gxmessage closes.

Within the here-document I'm essentially calling gxmessage thusly:
$ nohup gxmessage -timeout 0 -file abc.txt > /dev/null 2>&1 &

Any ideas on how I can allow the here-document to exit but allow the
gxmessage process to live on?

Thanks,

-- 
Mun