help with PHP -- this should be easy

[mcovey]

  
  <?php
   if  (strpos($_SERVER['HTTP_REFERER'], 'test.php') !== FALSE )  {
  	if (strpos($_POST['foo'], 'bar') !== FALSE) {
  		 echo "<h1>'bar' is correct!</h1>"; }
  	elseif (strpos($_POST['foo'], '$ar') !== FALSE) {
  		 echo "<h1>";
  		 echo $_POST['foo'];
  		 echo " rhymes with the right word, at least </h1>"; }
  	else {
  		 echo "<h1>";
  		 echo $_POST['foo'];
  		 echo " is WRONG</h1>"; }
  
   } else  {  }
  
  ?>

a nice small script to respond to the input of a form, and I need to make this happen:

when someone inputs anything that rhymes with bar, like car or star, it will say "well X rhymes." It seems easy, and i know it's not foolproof (like if they put war), but it's my second day of PHP.

oh by the way if anyone wants to see the form/page, go to http://metawire.org/~mcovey/test.php