Help to modify my code.

[Holbroom]

<?php 

$url = "http://172.31.244.170/~espresso/primary_uk/index.html"; 
$page = fopen($url, 'r'); 
$content = ""; 
while( !feof( $page ) ) { 
$buffer = trim( fgets( $page, 4096 ) ); 
$content .= $buffer; 
} 
  

$start = "Last updated: "; 
$end = "<\/footer>"; 
  

preg_match( "/$start(.*)$end/s", $content, $match); 
$mytext = $match[1]; 
echo "$mytext"; 
?>

Would somebody kindly modify the code I have above to return an "Offline message" if the URL times out (PC is offline or not connected), Many Thanks