Magento – how to set default value for fields in admin panel

If you want all the details please check the links provided by Alan Storm and others. As this has been documented extensively before I will only provide a simple example for the sake of answering the question.

1. Create your own extension with your namespace (called Vendor in the following) and extension name (Extensionname).

2. Add the file app/code/[codePool]/[Vendor]/[Extensionname]/etc/system.xml. From your text I assume that you already did that.

3. First important bit: when adding a new section, specify the correct tab name as specified in the system.xml under

   <config>
     <tabs>
       <[tabname] translate="label" module="[module]">
         <label>Tab name</label>
         <sort_order>10</sort_order>
       </[tabname]>
     </tabs>
   </config>
   

   E.g.

   <config>
     <sections>
       <yoursection translate="label" module="customer">
         <class>separator-top</class>
         <label>Your section</label>
         <tab>customer</tab> <!-- the important one -->
         <sort_order>10</sort_order>
         <show_in_default>1</show_in_default>
         <show_in_website>1</show_in_website>
         <show_in_store>1</show_in_store>
       </yoursection>
     </sections>
   </config>
   

4. Add your groups and fields as usual.

5. Second important bit add the section to the ACL in app/code/[codePool]/[Vendor]/[Extensionname]/etc/adminhtml.xml so that you can enter the section (after you have added the permission to the backend users and logged out/in again).

   <config>
       <acl>
           <resources>
               <admin>
                   <children>                 
                       <system>
                           <children>
                               <config>
                                   <children>
                                       <yoursection translate="title" module="customer">
                                           <title>Your section</title>
                                           <sort_order>10</sort_order>
                                       </yoursection>
                                   </children>
                               </config>
                           </children>
                       </system>
                   </children>
               </admin>
           </resources>
       </acl>
   </config>
   

Even without groups and fields you should be able to see the section.

partial answer

I manage to call my module controller via the button :

the controller class became :

class Mine_Custoptiontype_FilesstateController extends Mage_Adminhtml_Controller_Action
{
    public function updateAction()
    {   
        echo "ca va updater!";
    }    
}

the class instanciation in config.xml

...
 </global>

      <admin>
        <routers>
            <mine_custoptiontype>
                <use>admin</use>
                <args>
                    <module>Mine_Custoptiontype</module>
                    <frontName>custoptiontype</frontName>
                </args>
            </mine_custoptiontype>
        </routers>
    </admin>
</config>

and the button :

class Mine_Custoptiontype_Block_Adminhtml_Sales_Order_View extends Mage_Adminhtml_Block_Sales_Order_View {

    public function  __construct() {
        $this->_addButton('updatebutton', array(
            'label'     => Mage::helper('adminhtml')->__('SAVE ORDER'),
            'onclick'   => 'setLocation(\''.Mage::helper("adminhtml")->getUrl("custoptiontype/filesstate/update").'\')',
            'class'     => 'scalable save'
        ), 0, 100, 'header', 'header');

        parent::__construct();
    }

Now I need to post the radio input value and update the order… I am still surching for a solution. I read several posts on form submission using something like

$this->_addButton('save_and_continue', array(
             'label' => Mage::helper('blog')->__('Save And Continue Edit'),
             'onclick' => 'saveAndContinueEdit()',
             'class' => 'save' 
         ), -100);
         $this->_formScripts[] = "
             function saveAndContinueEdit(){
                editForm.submit($('edit_form').action + 'back/edit/');
             }
             ";

but I am not even sure I declared my input radio button correctly… As they are used as a product option configuration, maybe I should have used something like :

<input type="radio" class="input-text" name="product[options][{{option_id}}][label]" value="Checking">
<input type="radio" class="input-text" name="product[options][{{option_id}}][label]" value="Files_OK"></td>
<input type="radio" class="input-text" name="product[options][{{option_id}}][label]" value="Files_not_OK">

I would really appreciate any help please...