PHP Roll Dice

<?php 
function doDice($text){ //the main dice function
if(preg_match("/^(.*?)\[dice\]\s*(\d+)\s*d\s*(\d+)\s*\[\/dice\]/i", $text, $things)) { //if it matches only the [dice]1d10[/dice] then do without the motive
  return rolldice($things[2], $things[3], $things[1]); 
}elseif(preg_match("/^(.*?)\[dice=(.*?)\]\s*(\d+)\s*d\s*(\d+)\s*\[\/dice\]/i", $text, $things)){ //or if it does have [dice=My Motive]1d10[/dice] supply the motive.
  return rolldice($things[3], $things[4], $things[1], $things[2]); 
} //end motive check
} //end main function
 
function rolldice($dice, $sides, $originalText = null, $motive = null) 
{ //the core of the roll dice function 
   $total = 0; //the total value
   for ($i=1; $i <= $dice; $i++) //loop for the amount of dice 
   { 
      $dv = rand(1, $sides); //get a random number from 1 to the number of sides on the dice
      $total = $total + $dv; //add to the total.
   } //end our loop
$string = ($motive != null) ? "$originalTextRolling $dice dice with $sides sides &lt;$motive&gt;...Total value: $total" : "$originalTextRolling $dice dice with $sides sides...Total Value: $total";
//Above: set the string depending on if a motive is specified or not
return $string; //return the string from above with the original text from the post or other item
} //end the core function
?>

$message = doDice("Here is the original message and i'm rolling a dice with motive.. [dice=My Motive Here]1d10[/dice]");
print $message;