ClassWizard member variables.

I have a simple application based on the document/view "paradigm" with the CFormView base view class. I draw little checks and stuff and assign member variables to them. Eg. I'll put in a checkbox and assign it a BOOL m_CheckBox variable through ClassWizard. Now, in this same dialog I have a button that I want to be enabled/disabled depending on whether or not the box is checked. Apparently I can't just say m_button.EnableWindow(m_CheckBox) without first doing a call to UpdateData()... is this how it's supposed to be? And on a side question... does UpdateData() update -all- DDX variables for the particular dialog?

In terms of style and efficiency... what's better? Making a call to UpdateData() everytime I receive a message from the checkbox saying it's been clicked and using the BOOL m_CheckBox variable I created or creating a CButton m_CheckBox control variable that I can tinker with to get the value...

OnCheckBoxClicked(?)
{
UpdateData();
m_ButtonCtrl.EnableWindow(m_CheckBoxVar);
}

or

OnCheckBoxClicked(?)
{
m_ButtonCtrl.EnableWindow(m_CheckBoxCtrl.GetState() & 3);
}

Which one is "correct"? That "& 3" is in there to mask of the state to see if it's clicked or not... Thanks!