database exclusive used

Set A = CreateObject("Access.Application")
A.Visible = False
A.OpenCurrentDatabase (C:\MyDatabase\MyDatabase/mdb")

strMYSQL = "INSERT INTO tblLOG (MyField1) Values " & _
"(" & Mycontrol.Value & ")"


A.DoCmd.runSQL strMYSQL
A.Application.Quit
Set A = Nothing

My Excel application has a update log function. It works, but I got database
exclusive uses message.

It seems that the database locked by first uses. I close and quit the
application.

Can you please help me how to close and unlock the database using VBA?

Your information is great appreciated,