#!/usr/bin/php
<?PHP

$html = '<nls:txt>Help <b>And</b> Support</nls:txt>
        <p>
        <nls:txt>As this is not a public web site, its content is protected by an
            authentication system. In other words, users have to proof their
            authentication before they are allowed to enter. 
        </nls:txt>
        </p>
        <h2><nls:txt>How Login Works</nls:txt></h2>';

    $preg       =   '#(<nls:(\w*)([^>]*)>)(.*)(</nls:\\2>)#msU';

    if( !preg_match_all( $preg, $html, $match, PREG_SET_ORDER ) ) {
        echo "not found ?\n";
        exit;
    }
    
    print_r( $match );

?>