Error: Database Already Open

hi
i get the error "The database is already opened exclisively by another user" after running the following code. i ran the same code under the same conditions on my home pc and it worked fine.

Private Sub Command1_Click()

Dim dbs As Database
Dim qdf As QueryDef
Dim strSQL As String

Set dbs = CurrentDb
strSQL = "update Emp set Salary = 786+ val(text2)- val(text3) where EmpID = '& val(text1) &'"
Set qdf = dbs.CreateQueryDef("", strSQL)

End Sub