how to run extensions in the magento - magento-1.9

Question

i am a novice person to magento.I installed magneto 1.9.2.4 version.I need to create the extension for magento.I learned about the file structure of creating extension but cannot know how to run.Can anyone specify how to run the extension?
Advance Thanks!
/var/www/html/magento/app/code/local/Multidots/HelloWorld/etc/config.xml
<?xml version="1.0"?>
<config>
<modules>
<Multidots_HelloWorld>
<version>0.1.0</version>
</Multidots_HelloWorld>
</modules>
<frontend>
<routers>
<helloworld>
<use>standard</use>
<args>
<module>Multidots_HelloWorld</module>
<frontName>helloworld</frontName>
</args>
</helloworld>
</routers>
</frontend>
<admin>
<routers>
<helloworld>
<use>admin</use>
<args>
<module>Multidots_HelloWorld</module>
<frontName>admin_helloworld</frontName>
</args>
</helloworld>
</routers>
</admin>
</config>
/var/www/html/magento/app/etc/modules/Multidots_HelloWorld.xml
<?xml version="1.0"?>
<config>
<modules>
<Multidots_HelloWorld>
<active>true</active>
<codePool>local</codePool>
</Multidots_HelloWorld>
</modules>
</config>
/var/www/html/magento/app/code/local/Multidots/HelloWorld/controllers/IndexController.php
<?php
class Multidots_HelloWorld_IndexController extends Mage_Core_Controller_Front_Action{
public function indexAction() {
echo "Huhh...., I knew you can do it!!!n";
echo "Let's do it in proper way, you konow... ;) :D :P";
}
}
?>
i run this code using http://localhost/magento/helloworld also http://localhost/magento/index.php/helloworld but i got error
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can anyone suggest how to run?

Answer 1

I think you are asking for creating extension from scratch right?
Please check this link for creating simple extension.
http://inchoo.net/magento/programming-magento/magento-hello-world-module-extension/
And for run that extension please reload the front or backend of the Magento.
Thanks