I am creating MDI project with CFormView.
On Views Form dialog I placed a button.
And inserted one more dialog in project (IDD_DIALOG1)
Created One class(CDia) derived from CDialogEx which is using (IDD_DIALOG1) using "AddClass"
On Button click I written following code
And added appropriate header file "Dia.h"
On compiling it gives error CDialogEx undefined.
I am using Visual Studio 2010 Professional
Please help me to solve thia issue