title: name of type="action" in openerp button
body: <p>I've a problem when I want to make button in <code>type="action"</code>, it's really different with <code>type="object"</code>. I just want to make button that can connect one module to another.  It already exists in openerp for a few buttons of <code>type="action"</code>.  I just want to understand what is the function of <code>"name"</code> of this button? </p>
  
  <p>I have an example, I found this xml script in backend sale folder:</p>
  
  <pre><code>&lt;button name="%(action_view_sale_advance_payment_inv)d"
   string="Create Invoice"
   type="action"
   states="manual"
   class="oe_highlight"
   groups="base.group_user"/&gt;
  </code></pre>
  
  <p>when I installed sale module, then I see the xml script in frontend <code>sale.order.form</code>, it's already change into:</p>
  
  <pre><code>&lt;button name="278"
   string="Create Invoice"
   type="action"
   states="manual"
   class="oe_highlight"
   groups="base.group_user"/&gt;
  </code></pre>
  
  <p>What's happening with the <code>"name"</code>? Can anyone give me a simple button of <code>type="action"</code>?</p>