Removing text before and after keyphrase

Hello everyone,

I'm looking to turn this string:

$string = "jhdfgsdf984w5yisrek903_START_OF_WEBPAGE_http://www.google.com_END_OF_WEBPAGE"

into this string:

$string = "http://www.google.com"

before the phrase "_START_OF_WEBPAGE_" could be any types of symbol or character.

I've been trying to use regular expressions but can't seem to get them to work.

Many thanks for your help.

Stu

if (preg_match('/_START_OF_WEBPAGE_(.+)_END_OF_WEBPAGE/', $string, $matches)) {
$string = $matches[1];
} else {
$string = "";
}

Yeah?

$string = preg_replace('~/_START_OF_WEBPAGE_(.+?)_END_OF_WEBPAGE~','$1',$string);