When I run this script I get this error:-

Fatal error: Call to undefined function curl_init() in cheat.php on line 3


Source:

Code:
<?php
$url="http://google";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
$store = curl_exec ($ch);
curl_close ($ch);
$siteurl = substr($store, 485, 79);
?>

<META http-equiv="refresh" content="3;URL=<?php echo $siteurl; ?>">

Its meant to autorefresh the page.

Does anyone know how to fix this?