class TDateEdit not found

[notidaho]

Hallo, I hope English is OK but tell me if not.

I am trying to understand some delphi code written by somebody else.
I first had to install the ADS (Advantage Database Server) TDataSet components. I frequently get the message:

class TDateEdit not found

for some apps, and also when I try to build the entire program (over 50 units) I get:

cxTextEdit11 does not have a corresponding component

Can anyone suggest what components I need to install?

Many thanks,
Ian