To close the box after 10 seconds. Best is ofcourse to include some check to verify the user hasn't clicked yet. Probably set a %variable after the $input and check for it's presence, since $active doesn't work...
//timer 1 10 sendkeys n | echo -s $input(Perform action?,y)


I didn't write this piece of magic, qwerty did apparently http://www.mircscripts.org/comments.php?cid=1581

Code:
alias sendkeys {
  var %a = sendkeys $+ $ticks 
  .comopen %a WScript.Shell 
  if !$comerr { .comclose %a $com(%a,SendKeys,3,bstr,$1-) }
}


ps: this older thread asks for something similar