GetDiz Program

I have come by GetDiz program. It's a popular program and a replacement for Note Pad, it says.
It comes with 'black' backgraound colour, but it can be changed to other colours as we wish. Changed it to 'white' and it didn't work because the font is of white colour.
It has facility to 'copy' the text in it and 'paste' where cursor blinks.
Tried it but it wouldn't work.
If it does it would be an excellent one to have.
Could you please tell me how to get this copy and paste thing to work.
thanks, ben