function module_name_elements() {
	return array(
	'height' => array(
     	'#input' => TRUE,
     	'#process' => array('expand_height'),
     	'#element_validate' => array('height_validate'),
  	),
}

function expand_height($element) {
	// Assigning default values to element. You can override these values by passing your own values using "#default_value".
	if (empty($element['#value'])) {
    	$element['#value'] = array(
      		'feet' => '-',
      		'inch' => '-',
    	);
  	}
 
	$element['#tree'] = TRUE;
 
	$parents = $element['#parents'];
	$parents[] = 'feet';
    	$element['feet'] = array(
      	'#type' => 'select',
		'#default_value' => $element['#value']['feet'],
		'#options' => array('-' => '-', '2' => '2', '3' => '3', '4' => '4', '5' => '5', '6' => '6', '7' => '7', '8' => '8',),
		'#suffix' => t('ft.'),
    	);
 
	$parents = $element['#parents'];
    	$parents[] = 'inch';
    	$element['inch'] = array(
		'#type' => 'select',
		'#default_value' => $element['#value']['inch'],
		'#options' => array('-' => '-', '0' => '0', '1' => '1', '2' => '2', '3' => '3', '4' => '4', '5' => '5', '6' => '6', 
			'7' => '7', '8' => '8', '9' => '9', '10' => '10', '11' => '11'),
		'#suffix' => t('in.'),
    	);
 
	return $element;
}

function theme_height($element) {
  	return theme('form_element', $element, '<div class="container-inline">'. $element['#children'] .'</div>');
}

function module_name_theme() {
	return array(
		'height' => array(
      		'arguments' => array('element' => NULL))
  	);
}

function height_validate($element) {
  	if (trim($element['#value']['feet']) == '-' || trim($element['#value']['inch']) == '-') {
    		form_error($element, t('The specified height is invalid.'));
  	}
}

$user->height = array('feet' => '5', 'inch' => '8');
// Create element of 'type' height
$form['height'] = array('#type' => 'height',
		'#title' => t('Height'),
		'#required' => TRUE,
		'#default_value' => isset($user->height) ? $user->height : array('feet' => '-', 'inch' => '-'),
	);
 
//Access it in form_submit() like this
$height = $edit['height']['feet']. '-' . $edit['height']['inch'];

<php
function mymodule_theme() {
  	return array(
    	'phone' => array(
      	'arguments' => array('element' => NULL))
  	);
}
 
function mymodule_elements() {
	return array(
		'phone' => array(
     	'#input' => TRUE,
     	'#process' => array('expand_phone'),
     	'#element_validate' => array('phone_validate'),
  		),
  	);
}
 
function expand_phone($element) {
	if (empty($element['#value'])) {
    	$element['#value'] = array(
      		'part1' => '',
      		'part2' => '',
      		'part3' => '',
    	);
  	}
 
	$element['#tree'] = TRUE;
 
	$parents = $element['#parents'];
        $parents[] = 'part1';
        $element['part1'] = array(
      	'#type' => 'textfield',
		'#size' => 4,
		'#maxlength' => 3,
		'#default_value' => $element['#value']['part1'],
		'#prefix' => '(',
		'#suffix' => ')',
    );
 
	$parents = $element['#parents'];
        $parents[] = 'part2';
        $element['part2'] = array(
      	'#type' => 'textfield',
		'#size' => 4,
		'#maxlength' => 3,
		'#default_value' => $element['#value']['part2'],
		'#suffix' => '-',
    );
 
	$parents = $element['#parents'];
        $parents[] = 'part3';
        $element['part3'] = array(
      	'#type' => 'textfield',
		'#size' => 6,
		'#maxlength' => 4,
		'#default_value' => $element['#value']['part3'],
    );
 
	return $element;
}
 
function theme_phone($element) {
  	return theme('form_element', $element, '<div class="container-inline">'. $element['#children'] .'</div>');
}
 
function phone_validate($element) {
  	if (trim($element['#value']['part1']) == '' || trim($element['#value']['part2']) == '' || trim($element['#value']['part3']) == '' ||
  		!is_numeric($element['#value']['part1']) || !is_numeric($element['#value']['part2']) || !is_numeric($element['#value']['part3'])) {
    	form_error($element, t('The specified phone number is invalid.'));
  	}
}
?>

<?php
function mymodule_theme() {
  	return array(
    	'cardexpdate' => array(
       	'arguments' => array('element' => NULL))
	);
}
 
function mymodule_elements() {
	return array(
		'cardexpdate' => array(
     	        '#input' => TRUE,
     	        '#process' => array('expand_cardexpdate'),
     	        '#element_validate' => array('cardexpdate_validate'),
  		),
  	);
}
 
function expand_cardexpdate($element) {
	$next_month_date = strtotime("+1 month");
	$month = date('n', $next_month_date);
	$year = date('Y', $next_month_date);
 
	if (empty($element['#value'])) {
		$element['#value'] = array(
      		'month' => $month,
      		'year' => $year,
    	);
  	}
 
	$element['#tree'] = TRUE;
 
	$parents = $element['#parents'];
        $parents[] = 'month';
        $element['month'] = array(
      	'#type' => 'select',
		'#default_value' => $element['#value']['month'],
		'#options' => drupal_map_assoc(range(1, 12), 'cardexpdate_map_month'),
    );
 
	$parents = $element['#parents'];
        $parents[] = 'year';
        $element['year'] = array(
		'#type' => 'select',
		'#default_value' => $element['#value']['year'],
		'#options' => drupal_map_assoc(range($year, 2020)),
    );
 
	return $element;
}
 
function theme_cardexpdate($element) {
	return theme('form_element', $element, '<div class="container-inline">'. $element['#children'] .'</div>');
}
 
function cardexpdate_validate($element) {
	$month = $element['#value']['month'];
	$year = $element['#value']['year'];
 
	$exp_date = mktime(0, 0, 0, $month, date('j'), $year);
 
	if ($exp_date < time()) {
    	form_error($element, t('The specified expiry date is invalid.'));
  	}
}
 
function cardexpdate_map_month($month) {
	return format_date(gmmktime(0, 0, 0, $month, 2, 1970), 'custom', 'm', 0);
}
?>