Use this custom code wheather in a page.tpl.php file or you can use it in creating a new drupal block and showing block in the particular region
Place the flag images in you theme folder named like fr.png for (French)
en.png for (English) etc.
<?php
$lang_links = array();
foreach (language_list() as $language) {
//genrate the image name
$image = '/'. $language->language.'.png';
//adding link information to the array
$lang_links[$language->language] = array('href' => $_GET['q'], 'title' => $language->native, 'image' => $image, 'name' => $language->name, 'options' => array('language' => $language, 'attributes' => array('class' => 'language_link'), 'html' => true));
}
// Allow modules to provide translations for specific paths for the links
drupal_alter('translation', $lang_links, $_GET['q']);
foreach ($lang_links as $datalink) {
$flag = '<img title="'. $datalink['name'].'" alt="'. $link['title'] .'" src="' .base_path().path_to_theme().$datalink['image'] .'"/>';
$output .= l($flag, $link['href'], $link['options']);
}
print $output;
?>
Note: Remember to install languages and enable the path prefix option from the configuration settings