Remote access to file through file editor on ubuntu

While taking some measure on one of my softwares, I noticed instead of going through the ftp every time to get the results, I could just open some text editor. For this things I installed gedit on the Ubuntu remote machine I'm working on. I tried the following command

gedit filename.txt

Cannot open display: 
Run 'gedit --help' to see a full list of available command line options.

As you can see it produced that error. The problem I had (and apparently is quite common), it's the fact that when I logged on my remote machine through ssh I forgot to include the correct flag:

ssh -X username@my.server.com

Mind the capital X as flag. I kept logging in with lowercase x which lead of course to wrong behaviour.
I'm sorry for the small update, but I noticed many many programmers asked this on StackOverflow, so I though it may be useful keeping it written somewhere :-).