no double

[grlayouts]

hi,

 

i have a chat box just a sim php one with the code

 

<input name="submit2" type="submit" value="Say it!" />

                      <?php

if ($action == postmsg) {

if (empty ($chat)) {

	print "Duh... fill out all fields.";

	exit;

}

mysql_query("insert into tagboard (name, comments, date) values('$stat[user]','$chat',now())") or die("Could not add updates.");

}

?>

 

because this is on my main page alot of people hit f5 to reload and it posts the message again. is there any way to chnage the code so that you cant post the same message twice?