how do I change a button text and command

[Ramprasad A Padmanabhan]

Hi all,
  I am a Tk newbie , I have a tk windows with two buttons , my 
requirement is to change to the button text when it is pressed
How do I do this ?

$button = $mainwindow->Button(-text => "find", -command => \&search );
.....
sub search {
   $button->text("Wait");    # This does not work
   .....
}
THanks
Ram