title: Cannot connect to X server :0.0 with a Qt application
body: <p>Compiling on Fedora 10.</p>
  
  <p>I have just started my first qt GUI application. I used all the default settings.</p>
  
  <p>Its just a simple form. It builds OK without any errors. But when I try and run the application. I get the following message:</p>
  
  <pre><code>Starting /home/rob/projects/qt/test1/test1/test1...
  No protocol specified
  test1: cannot connect to X server :0.0
  </code></pre>
  
  <p>Thanks for any advice,</p>