An application sends an EM_GETMODIFY message to determine if the contents of an edit control have been modified.
wParam
This parameter is not used.
lParam
This parameter is not used.
The return value is TRUE if the edit-control contents have been modified, or FALSE if they have remained unchanged.
Windows maintains an internal flag indicating whether the contents of the edit control have been changed. This flag is cleared when the edit control is first created, and may also be cleared by sending a EM_SETMODIFY message.
EM_SETMODIFY