Hi Pamela,
I tried that you said. But in that case textbox not seeing at design time. Those generating at runtime. So you cant implement any property or method at design time. I found the solution.
If you do that you will see your owntextbox classes at design time:

DEFINE CLASS xcolumn as Column
ADD OBJECT mytextbox as _mytextbox
currentcontrol="_mytextbox"
sparse=.f.




PROCEDURE Init

ENDPROC


Thanks,