function gt_user_login_redirect( $redirect_to=null, $request=null, $user=null ) {
	
	global $user;
	//the default home page if none of the criteria below is met
	$redirect_url_after_login = home_url();
	
	
	require_once( ABSPATH . 'wp-includes/pluggable.php' );
	$is_a_member = false;
	
	if ( Groups_Group::read_by_name( 'Simple Users' ) ) {
		
		$group = Groups_Group::read_by_name( 'Simple Users' );
		
	}
	
	if ( isset( $user->roles ) && is_array( $user->roles ) ) {
		
		//check for admins
		if ( in_array( 'administrator', $user->roles ) ) {

			//if the admin is logged, redirect to the dashboard
			$redirect_url_after_login = admin_url();
		
		} else if ( $is_a_member = Groups_User_Group::read( $user->ID , $group->group_id ) ) {
			
			//if the logged user belongs to Simple Users group, redirect to my contact page
			$redirect_url_after_login = get_permalink( 3399 );
			
		}
	} 
	
	
	return $redirect_url_after_login;
}
add_filter( 'login_redirect', 'gt_user_login_redirect', 10, 3 );