<?php
$members = array(
array(
"loc" => "Ontario",
"first" => "Bob",
"screen_name" => "fooArt"
),
array(
"loc" => "Atlanta",
"first" => "Sal",
"screen_name" => "TIMMY!"
),
array(
"loc" => "Panama",
"first" => "Mick",
"screen_name" => "Analog"
),
array(
"loc" => "Pensacola",
"first" => "A",
"screen_name" => "Franky"
),
array(
"loc" => "McPherson",
"first" => "Anna",
"screen_name" => "annie_23"
)
);
usort( $members, 'custom_sort' );
function custom_sort( $m1, $m2 ){
return strtolower( $m1['screen_name'] ) > strtolower( $m2['screen_name'] );
};
print_r( $members);