You may try a different alias, say, myTable. Also add exclusive keyword in USE command and in ALTER TABLE command you may need

ALTER TABLE (dbf('myTable')) ...

>thank you both but.
>i get error message Alias name is already in use
>

>thisform.text1.value=getfile("dbf")
> thisform.text1.value=JUSTSTEM(thisform.text1.Value)
>
>cTable=alltrim(thisform.text1.Value)
>Use (cTable) in 0 again alias tmp1
>If Type('tmp1.ccc')<>'U'
>  Alter Table tmp1 Drop Column ccc
>Endif
>use in tmp1
>

>>>hi,