If class textbox_char defined in the program, then try:
.....
set procedure to dataform
Define Class CodesMainTxtChar As textbox_char
....



>I have this code in a prg.
>
>Define Class CodesMainTxtChar As textbox_char Of dataform
>...
>
>EndDefine
>
>While compiling the project I receive this error:
>
>Program codesmain.prg has the following errors:
> Program DATAFORM - Undefined
>
>I tried EXTERNAL CLASS dataform but I did not help.
>How can I prevent this error?
>
>Thanks in advance
>Anthony