title: Displaying the value of a textbox in other parts of a report
body: <p>In a report table there is this formula to calculate a subtotal for an invoice. This is the formula:</p>
  
  <pre><code>=Sum(Fields!LineTotal.Value)
  </code></pre>
  
  <p>The textbox is called TextBoxSubTotal. I would like to display this in another part of the report such as in the header area where I display that subtotal, tax, shipping charge and also a total due.</p>
  
  <p>Can you tell me how to display this value in TextBoxSubTotal in other parts of the report?</p>