Sergey,

You are right. It works like this:
cUpdateString = [UPDATE BEST SET ] + lprFieldName + [ = '] + lprFieldValue + ['] + ;
[ WHERE BESTNR=] + Transform(nBestnr)
but it does not work like this:
lcUpdateString = [UPDATE BEST SET ] + lprFieldName + [ = '] + [lprFieldValue] + ['] + ;
[ WHERE BESTNR=] + Transform(nBestnr)
as was proposed to overcome the problem with doubble quotes. However, when the command is written like the first one above I find now no problem to transfer doubble quotes to the SQL-table.