Fatal error: Cannot redeclare function

I want install Commerce Them but get error: Fatal error: Cannot redeclare commercetheme_preprocess_html() (previously declared in /home/kompiute/domains/kompiuteriui.lt/public_html/sites/all/themes/commercetheme/template.php:29) in /home/kompiute/domains/kompiuteriui.lt/public_html/sites/all/themes/commercetheme/template.php on line 114

<?php

/**
* @file
* Process theme data.
*
* Use this file to run your theme specific implimentations of theme functions,
* such preprocess, process, alters, and theme function overrides.
*
* Preprocess and process functions are used to modify or create variables for
* templates and theme functions. They are a common theming tool in Drupal, often
* used as an alternative to directly editing or adding code to templates. Its
* worth spending some time to learn more about these functions - they are a
* powerful way to easily modify the output of any template variable.
*
* Preprocess and Process Functions SEE: http://drupal.org/node/254940#variables-processor
* 1. Rename each function and instance of "adaptivetheme_subtheme" to match
* your subthemes name, e.g. if your theme name is "footheme" then the function
* name will be "footheme_preprocess_hook". Tip - you can search/replace
* on "adaptivetheme_subtheme".
* 2. Uncomment the required function to use.
*/

/**
* Preprocess variables for the html template.
*/

function commercetheme_preprocess_html(&$vars) {
global $theme_key;

// Two examples of adding custom classes to the body.

// Add a body class for the active theme name.
// $vars['classes_array'][] = drupal_html_class($theme_key);

// Browser/platform sniff - adds body classes such as ipad, webkit, chrome etc.
// $vars['classes_array'][] = css_browser_selector();

}
// */

/**
* Process variables for the html template.
*/

function commercetheme_process_html(&$vars) {
}
// */

/**
* Override or insert variables for the page templates.
*/

function commercetheme_preprocess_page(&$vars) {
}
function commercetheme_process_page(&$vars) {
}
// */

/**
* Override or insert variables into the node templates.
*/

function commercetheme_preprocess_node(&$vars) {
}
function commercetheme_process_node(&$vars) {
}
// */

/**
* Override or insert variables into the comment templates.
*/

function commercetheme_preprocess_comment(&$vars) {
}
function commercetheme_process_comment(&$vars) {
}
// */

/**
* Override or insert variables into the block templates.
*/

function commercetheme_preprocess_block(&$vars) {
}
function commercetheme_process_block(&$vars) {
}
// */

/**
* Preprocesses the wrapping HTML.
*
* @param array &$vars.
* Template variables.
*/
function commercetheme_preprocess_html(&$vars) {
// Setup IE meta tag to force IE rendering mode.
$meta_ie_render_engine = array(
'#type' => 'html_tag',
'#tag' => 'meta',
'#attributes' => array(
'content' => 'IE=edge,chrome=1',
'http-equiv' => 'X-UA-Compatible',
)
);
// Add header meta tag for IE to head.
drupal_add_html_head($meta_ie_render_engine, 'meta_ie_render_engine');
}