procedure SetValue(dbf, f :integer; s :string; d :double);

SetValue writes the specified value to the internal memory. If you want to write this information to a file you have to write then WriteRecord.
The function accepts both a string value and a numeric value. The fucntion will use one of them according a field type.

var dbf :integer; r :integer; begin dbf := OpenBase( 'filename.dbf' ); if dbf <> 0 then begin for r := 0 to RecCount(dbf)-1 do begin ClearRecord(dbf); SetValue(dbf, 0, 'some string', 123.45); SetValue(dbf, 1, nil, 67.89); SetValue(dbf, 2, 'one more string', 0); WriteRecord(dbf, r); end; CloseBase(dbf); end; end.