function playWithHtml($OutputHtml){


    if(!preg_match_all("/<a>]+)>(.*)</a>/Usi",$OutputHtml,$Links)){


    return $OutputHtml;


   }


    $InnerHtmls=$Links[2];


    $LinkTags=$Links[1];


    foreach($LinkTags as $LinkTag){


   $OldLinkTag=$LinkTag;


      if(preg_match("/href=[\"']?http/i",$LinkTag)){


         if(!preg_match("/\starget=/i",$LinkTag)){


         $LinkTag=trim($LinkTag).' target="_blank"';


         $OutputHtml = str_replace($OldLinkTag,$LinkTag,$OutputHtml);


         }               


      }      


   }


    foreach($LinkTags as $LinkTag){


   $OldLinkTag=$LinkTag;


      if(preg_match("/href=[\"']?http/i",$LinkTag)){


         if(!preg_match("/\srel=/i",$LinkTag)){


         $LinkTag=trim($LinkTag).' rel="nofollow"';


         $OutputHtml = str_replace($OldLinkTag,$LinkTag,$OutputHtml);


         } 


      }      


   }


    return $OutputHtml;


}

$sting = playWithHtml($sting);

/**


 * @author Guardian


 * @return <boolean>


 * EXAMPLE USEAGE:


 * if(!is_spider()) {


 * // display hidden content here


 * } 


 */


function is_spider(){


  $spiders = array(


    'Googlebot', 'Yammybot', 'Openbot', 'Yahoo', 'Slurp', 'msnbot',


    'ia_archiver', 'Lycos', 'Scooter', 'AltaVista', 'Teoma', 'Gigabot',


    'Googlebot-Mobile'


    );


// Loop through each spider and check if it appears in


// the User Agent  


   foreach ($spiders as $spider)  


     {


       if (preg_match('/'.$spider.'/i', $_SERVER['HTTP_USER_AGENT']))


        { return TRUE; }


      }


      return FALSE;


}

function user_validate_bogus_email($mail){


   global $nukeurl;


   // http://drupal.org/node/780476#comment-2887028


    // reads an entire file and stores it into an array so each line of the file is


    // stored into a new element in $spamlist_array.


    /*


        $spamlist_array[0] = 'This is line 1';


        $spamlist_array[1] = 'This is line 2';


    */


    $spamlist_array = file($nukeurl.'/includes/spamlist.txt');





    // iterates till the end of the file where each element of the array is represented as


    // $line_num and the actual value as $value


    /*


        $spamlist_array[$line_num];


    */


    foreach ($spamlist_array as $line_num => $value){


        // we want to check whether the current line ($value) is in $mail


        // we are not simply checking for $value because it has some type of character that makes the strpos()


        // function fail (most probably the new line character)


        $realvalue  = substr($value, 0, strlen($value) - 1);    // string to search in, start_pos, length


        $pos = strpos($mail, $realvalue);


        if ($pos === false){


        return true;


        }else{


      return false;


        }


    }   


}





function validate_mail($email) {


    if(strlen($email) < 7 || !preg_match("/\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/", $email) || 


   user_validate_bogus_email($email) === false) {


// These next 3 lines have been commented out by Raven on 1/14/2007.


// Reason being, this function should only validate the email and return to the calling script.


// The calling script should handle the validation results.


//        OpenTable();


//        echo _ERRORINVEMAIL;


//        CloseTable();


      return false;


    } else {


        return $email;


    }


}

$email = 'you@atyourdomain.com';


if(filter_var($email, FILTER_VALIDATE_EMAIL)) {


    // this is valid proceed


}


else {


    // filter again with RN function in mainfile.php


validate_email($email);


}