strSQL = "Update TimeLog " & _
    "SET TimeEnd = #" & Format(Me!txtTime, "hh:nn:ss") & "#, " & _
    "Type_Of_Duty = '" & Forms!frmTimeClock!Combo508 & "', " & _
    "Flight_Time = #" & Format(Forms!frmTimeClock!Flight!Flight_Time, "hh:nn:ss") & "# " & _
    "WHERE EmployeeID = " & Forms!frmLogin!cboEmployee & " " & _
    "AND TimeEnd Is Null;"