XML Parse Error

[adrwm]

This code parses weather XML to display current temperature, sometimes it doesn't load the XML file and displays some PHP error code. What can be added to display "Temperature not available"

Here's the code:

<?php 
$xml_vancouver = simplexml_load_file('http://www.weather.gov/xml/current_obs/CYVR.xml'); 
$vancouver = $xml_vancouver->temp_c; echo 
$vancouver  . "&#176;"; 
?>

[dagon]

define "some PHP error code"

[adrwm]

It cannot locate the weather.gov XML file, so it will display a similar error to a PHP include cannot locate.