I am sorry for bothering you with what is probably a simple question but I am not creative enough to come up with the proper search keywords when I've tried searching this on the screen-users' website or on google. Whenever I try to pull up an application which requires X when I am using screen I get an error telling me that I can't connect to the local X server. This isn't a problem on a different machine that I have, in fact, using that machine I can log into the machine with a problem, start a screen session and pull up X applications. What should I look for on the machine with problems that will fix my problem?