Object required in 'CNO(...)'

Hi,

This is my first time using  DIADEM and VB scripting, apologies in advance, if my question does not make more sense. In the below line of code, i am looking for "If The Definition channel is present or not "

If CNo(GroupTxt & "id_"& TempEmisType & TempChnStr & "Definition_").Properties("Unique_Definition").Value>0 Then

but, its throwing the error saying: Object required :'CNO(...)'

for your reference the above variables hold this values :

GroupTxt  1,

TempEmisType - emissions

TempChnStr-stream

And when i am using the old code, which i need to do certain modifications but majority of syntax is same, its still working, old code is:

If CNo(GroupTxt & "Ad_"& TempEmisType & TempChnStr & "DefinitionUnique_")>0

Any help is highly appreciated.
Thanks in Advance