title: Which Event Intercepts When a Textbox Changes Value Via Access VBA Code
body: <p>I'm changing the values of some textboxes of an Access form automatically. their control sources are as follows:</p>
  
  <pre><code>=SeImed(LucroBrutoOperacoes([txt_VendaValor];[txt_CompraValor])&gt;=0;LucroBrutoOperacoes([txt_VendaValor];[txt_CompraValor]);Nulo)
  </code></pre>
  
  <p>so, when the related fields in the if clause "SeImed" (Iif, in english), a text field changes its value to the calculated value or to null ("Nulo"), as shown in the formula. this is working pretty fine. what I need is to intercept when this change happens, which cannot be done by Change or AfterUpdate or Dirty events, for instance. I tried them all, unsuccessfully. if any of you know how to intercept this value change, please, help me. I'd appreciate your help.</p>
  
  <p>thanks in advance.</p>