Špatně zapsaný regExp

<?php
function specialChars($text, $back)
{
  if($back==true)
  {
    $rext=preg_replace("/'/", "#39;", $text); 
    $text=preg_replace("/\"/", "#22;", $text);
    $text=preg_replace("/\`/", "#96;", $text);
    $text=preg_replace("/(\\\\)/", "#92;", $text);
    //$text=preg_replace("/\$/", "#36;", $text);
  }
  else 
  {
    $arr=Array();
    $arr["39"]="'";$arr["22"]="\"";$arr["96"]="`";$arr["92"]="\\";$arr["36"]="\$";
    $text=preg_replace("/#(..);/", $arr["$1"] ,$text);
  }
  return $text;
}
?>