if($submit){
$result3 = mysql_query("INSERT INTO `bd` VALUES(NULL, '".$_POST['post']."', '".$_POST['nik']."')");
}?>
    
<form action="" method="post" >
Ваш ник: <input type="text" name="nik" value="Гость" /><br />
<textarea cols="100" rows="10" name="post"></textarea>
<input type="submit" name="submit" value="отпавить" />
</form>