>i try as under, error message Object "main1" is not found
>

>USE main1
>main1.date = STRTRAN(main1.date, "/", "_")&&
>

Then you should not be asking us. You are opening a table called "main1".
If the table does not open or is not found, look to see why. It does not exist, or is not in the search path, or you are not using the correct table name, or...

Another issue: Is main1.date a date-type field?
If it is, you cannot do STRTRAN() on it as it only works for character fields.