GetDlgItem error

[alexbo]

Hi everybody,
I'm programming in MFC, I have the following problem.

I created in the resource editor a CCommandButton that has the following id IDC_CONF_PASS_ATH_DETT the dialog is in an ActiveX enviroment.

then i wrote the following code:

<code>
GetDlgItem(IDC_CONF_PASS_ATH_DETT)->ShowWindow(FALSE);
</code>

because the code dumped i wrote even another version

<code>
CCommandButton *b;
b=(CCommandButton *)GetDlgItem(IDC_CONF_PASS_ATH_DETT);
b->ShowWindow(TRUE);
</code>

and discovered in Debug that b has a NULL value and that's why it dumped.
but why b has a NULL value

Any Idea thanks Alex