Close a data file.
Close the data file when there is no longer any need to read from or write to it.
Set fileno to the value specified when opening the data file.
private SNO$ private QTY$ private BARDATA$ open "TESTDATA.DAT" as #1 ' open data file field #1, 3 as SNO$, 5 as QTY$, 13 as BARDATA$ ' define fields