# CLICK.MS2 - Banner Ad System
#
# This program is called whenever someone clicks on a banner ad.  It updates
# the .STAT file for the ad and redirects the user to the URL associated
# with it.  You do not need to reference this program directly anywhere,
# that is taken care of in AD.MS2

ad = varget( "arg", 3 )
fn = "ms2/ads/" + ad + ".cfg"
if input = open( fn )
   line = read( input )
   expiry = first( line ) + " 00:00:01"
   maxdisplays = num( nth( line, 2 ) )
   maxclicks = num( nth( line, 2 ) )
   text = read( input )
   image = read( input )
   width = read( input )
   height = read( input )
   url = read( input )
   close( fn )
   if expiry > time()
      redirect( url )
      fn = "ms2/ads/" + ad + ".stat"
      displayed = 0
      clicked = 0
      if input = open( fn, "r+" )
         displayed = num( read( input ) )
         clicked = num( read( input ) )
         rewind( input )
      else
         input = open( fn, "w" )
      endif
      n = 0
      while lockf( input ) == 0 and n < 200
         n = n + 1
      endwhile
      clicked = clicked + 1
      write( input, displayed, "\n" )
      write( input, clicked, "\n" )
      close( input )
   endif
endif