Command: wait_key
  
Syntax: 
  include get.e
  i = wait_key()
  
Description: 
  Return the next key pressed by the user. Don't return until
  a key is pressed.
  
Comments: 
  You could achieve the same result using get_key() as follows:
  
  while 1 do
  k = get_key()
  if k != -1 then
  exit
  end if
  end while    
  
  However, on multi-tasking systems like Windows, Windows NT,
  or OS/2 this "busy waiting" would slow the system down. 
  wait_key() lets the operating system do other useful work 
  while your program is waiting for the user to press a key.
  
  You could also use getc(0), assuming file number 0 was input 
  from the keyboard, except that you wouldn't pick up the special
  codes for function keys, arrow keys etc.
  
See Also: 
  get_key, getc
  
