Lets you know what is going on with a variable in php.

Debug

function debug(&$var, $r = NULL) {
  // if $var is an empty string, we're being called recursively
  // this is an extreme guess, and might cause problems
  
  // now we determine the variable name
  $old = $var;
  // var = $new = "unique".rand()."value";
  $new = $var;
  $var = "unique".rand()."value";
  $new = $var;
  $vname = FALSE;
  foreach($GLOBALS as $key => $val) {
    if($val === $new) $vname = $key;
  }
  $var = $old;
  $n = $vname;
    
  if ($r == null) {
    echo "<div style='text-align: left;margin-top: 1em; margin-bottom: 1em; font-size: 110%; border: 1px solid #ccc; background: #efefef; padding: .5em; font-family: monospace;'>";
    echo "<div style='padding: .2em; margin-bottom: .2em; border: 1px solid #ccc; background: #fff;'>";
    echo "<span style='padding-right: .2em; float: right; color: red;'>";
    echo gettype($var);
    echo "</span>";
    echo "<span style='color: green;'>\$" . $n . "</span></div>";
  } else {
    echo "<div style='margin-left: .5em;'>";
  }
  
  // if $var is an array, we need to give it some special stuff
  if (is_array($var)) {
    echo "<div style='border-bottom: 1px dotted #ccc; padding-bottom: .5em; margin-bottom: .5em;'>";
    // for each $key=>$value pair
    foreach ($var as $k=>$v) {
      // we set $c (count) here as an empty string so it won't do anything, if we change it, we need to alter the display/layout
      $c = "";
      if (count($v) != 1) {
        $c = count($v) . " items";
      }
      // if $c is empty the results will be displayed next to the $k,
      // otherwise we're display the number of items, then on a new line, go over them
      echo "<span style='font-weight: bold;'>$k</span> &rarr; $c";
      if (is_array($v)) {
        debug($v, true);
      } else {
        echo $v . "<br />";
      }
    }
    echo "</div>";
  } else {
    echo $var;
  }
  echo "</div>";

}