OK. In any case, if you do a SELECT - SQL command (select ... into cursor ... nofilter), you can use reccount(). Even without the NOFILTER, the variable _tally will tell you how many records were selected. (Copy it to a variable immediately, because many commands will affect the variable _tally.)

By the way, it is recommended to use the HTML code PRE for program code - that way, spaces will be maintained, and automatic word wrap is turned off. I am formatting your code as an example; click on "REPLY" to see how the codes look:

>Hello Hilmar
>
>Thanks for your reply because that help me to understand better how work the RECCOUNT(), also i solve my problem writing my code and declare a variable "lncontador" to keep the value of the numbers of rows in my grid (Cursor) , like this:
>

Select ox
if ox.olorigem = 'CX90'

    select oy
    lncontador = 0
    scan
        lncontador = lncontador + 1
    endscan
    if lncontador > 1
        msg("Não pode ter mais que uma linha," + CHR(13) + ;
            "pois trata-se de uma Letra")
        return .F.
    endif
endif
select ox