finding minimal value of a simplexml object in php

minimal-xml-value.php

function find_min_rent($xml, $floorplanid) {
  $min_rent = 999999; // a ridiculously high number
  foreach($xml->xpath("/PhysicalProperty/Property/Unit[@FloorplanID='$floorplanid']") as $unit) { 
    if($unit->EffectiveRent['min'] < $min_rent) {  // save this rent amount if it's the lowest so far
      $min_rent = $unit->EffectiveRent['min'];
    }
  }
  return $min_rent;
}