Assign an output of DB query to a custom defined field in QC 11

HI All,

             I have the below logic to get the value from QC DB, I am printing the value and it looks fine, but i am not able to assign the value to the user defined field....please help me here

Sub TestPlan_Test_Autoid

set td = TDConnection

set com = td.command
com.CommandText = "select max(convert(int, TS_USER_07)) from TEST"
set rec = com.Execute
msgbox rec.FieldValue(0)
newValue = rec.FieldValue(0) + 1

msgbox newValue              ' I AM ABLE TO GET CORRECT VALUE TILL THIS POINT

Test_Fields("TS_USER_07").Value = newValue               'THIS STEP DOESNT WORK..... I am hoping variable newValue's value will be assigned to field "TS_USER_07"

Test_Fields("TS_USER_07").IsReadOnly = true
set com = nothing
' set rec = nothing
set td = nothing

End IF

End Sub

When i print - "msgbox newValue"  I am getting the exact value what i expected, but when i am trying to assign the same value to a field "Test_Fields("TS_USER_07").Value = newValue", then its coming as blank.