title: Mule Using MEL in Custom Business Events component
body: <p>Please advise how I need to use MEL in Custom Business Events component, Key Performance Indicators. According to MEL documentation, I need to use the expression <strong><em>#[xpath('//xpath/expression')]</em></strong>  </p>
  
  <p>To get access to XML message I use the following expressions:</p>
  
  <pre><code>#[xpath('/Invoices/invoice')] 
  #[xpath('//Invoices/invoice/invoiceHeader/InvoiceNo', message.payload)]
  #[xpath('/Invoices/invoice/invoiceHeader/InvoiceNo/text()')]
  </code></pre>
  
  <p>and etc.
  No results. Please help.</p>