title: Can I detect the display size/resolution in Emacs?
body: <p>I'd like to change the window/frame size of my XEmacs based on the current display resolution.</p>
  
  <p>This is useful when I run my laptop either by itself or attached to a docking station with an external monitor. In either situation, I'd like Emacs to detect the primary screen resolution and adjust its main window frame size accordingly when I start it up.</p>