Passing a GET value from HTML form to Twitter API 1.1 PHP -

i'm new , learning advice can give :) i'm making simple tool retrieve specific data twitter api 1.1 request school project. i'm using j7mbo's twitterapiexchange.php , format. created html form pass data array , can post requests api without problem. can print specific data request api when enter variables $getfield in php, when try , use form send data requests following errors:

notice: undefined offset: 1 in /var/www/exp/twitterapiexchange.php on line 158

warning: invalid argument supplied foreach() in /var/www/exp/screen1.php on line 31

here code:

    ini_set('display_errors', 1);      if(!empty($_get ['screen_name'])) {     require_once('twitterapiexchange.php');       $settings = array(     'oauth_access_token' => "my_key_here",     'oauth_access_token_secret' => "my_key_here",     'consumer_key' => "my_key_here",     'consumer_secret' => "my_key_here",     );      /** url rest request, see: https://dev.twitter.com/docs/api/1.1/ **/     $url = 'https://api.twitter.com/1.1/friends/list.json';     $getfield = $_get['screen_name'];     $requestmethod = 'get';      /** note: set field before calling buildoauth(); **/     $twitter = new twitterapiexchange($settings);     $response = $twitter->setgetfield($getfield)                 ->buildoauth($url, $requestmethod)                 ->performrequest();      ##this prints out fields interested in##      $arrresults = json_decode($response,true);      foreach ($arrresults['users'] $arrsearchresult) { $strtweet = $arrsearchresult['created_at'] ; $strtweet1 = $arrsearchresult['screen_name'] ;     print_r("<div class='tweet'>$strtweet $strtweet1</div>"); }            }      ?>     <h3>enter name here</h3>     <form action="" method="get">     <input type="text" name="screen_name" /><br />     <input type="submit" />     </form> 

so, i'm thinking request being malformed before oauth, because same errors when don't have access keys in oauth array.

in post requests api, form data passed directly api call array, requests built differently, , i'm not seeing how pass form data it. work fine:

    $getfield = '?screen_name=twitter_screen_name'; 

it's when try $getfield = $_get['screen_name']; goes wrong. time, sorry if noob stuff annoying :3

if $getfield = '?screen_name=twitter_screen_name'; works without form data, should need change line

$getfield = $_get['screen_name']; 

to

$getfield = "?screen_name=".$_get['screen_name']; 

assuming you're passing through @handle through in form

also, (this not pertinent issue) line if(!empty($_get ['screen_na... shouldn't have space inbetween $_get , [.