question about quickform behaviour

Hi all, I am trying to let htmlspecialchars() modify a the value of a quickform text element, like this: $headingElement =& $form->getElement('heading'); $val = htmlspecialchars($headingElement->getValue()); $headingElement->setValue($val); /// after this the value of the element has been correctly changed, but when I retrieve its value for storage elsewhere in my app, the old value is returned. I can see that _submitValues still holds the old value. So i guess my question in short is: How should I modify the value of an element *before* i call the form's validate()? Thanks for your time, hans PS: The reason why I need to do this is that as part of my validation process, i have to check for the xml validity of the input, in case you where wondering.