ask)
    </pre>

    <p>You can find definitions for all the window masks in the Apple
    Developer documentation
    for <a href="http://developer.apple.com/documentation/Cocoa/Reference/ApplicationKit/Classes/NSWindow_Class/Reference/Reference.html#//apple_ref/doc/uid/20000013-89097">NSWindow
    Constants</a>.</p>

    <p>Passing the window mask as the next argument gives us this
    expression:</p>

    <pre>
(ns:with-ns-rect (r 100 100 400 300)
  (#/initWithContentRect:styleMask:backing:defer: 
   my-