Know if Record is lock

I want to know if a record is used by other user, if it is then i want to disabled the save command button. I do this so that the user can only see the content but cannot save it if they have done some correction. The problem is that still other user can do some changes in the database since this code cannot determine that the record is used by others.
I dont know if this is the right way to do this but my code is:

if Adostinfo.LockType = adLockPessimistic then
        cmdSave.enable=false
else
        cmdSave.enable=true
end if

txtSName.text=adostinfo.recordset!stSName
txtFname.text=adostinfo.recordset!stFname

end sub

private sub cmdSave_click()
     adostinfo.recordset!stSName=txtSname.text
     adostinfo.recordset!stFname=txtFname.text
     adostinfo.recordset.update
     adostinfo.recordset.close
end sub