how find value of javascript variable with regex?

Question

I want RegEx in php that find value of js variable in my html page. Like this:

varName = \"http://sample.com\";

Answer 1

Something like that... but it could be extremely more complicated with the complexity of the js code

<?
$varname = "varName";
preg_match('/'.$varname.'\s*?=\s*?(.*)\s*?(;|$)/msU',$html,$matches);

if(count($matches>1)) {
    print($matches[1]);
}


?>