I know I must be doing something wrong but can any one let me know, how to get this working ?

If ( HowManyStandOffs =< 0 Lookup ("tFTPULL_RTD", "text1",  If ( HowManyStandOffs2 =< 0 Lookup ("rFTPulls_TR", "text1", If( HowManyStandOffs3 =< 0, Lookup("rHMSO_3", "text1", lookup ( "rFT_Pulls" "Description" )))))))

Not an everyday programmer, so if you can change it to work, rather than just telling me what to change. 

This works perfect, but adding other if' will not pass checking.

if( HowManyStandOffs <= 0 , Description   , lookup "tFTPULL_RTD" "Text1")

Relationship name "tFTPULL_RTD"

Field Name "Text1"

if( HowManyStandOffs <= 0 , Description , lookup "tFTPULL_RTD" "Text1" , if( HowManyStandOffs2 <= 0 , Description , lookup "rFTPulls_TR" "Text1", if( HowManyStandOffs3 <= 0 , Description , lookup "rHMSO_3" "Text1")))  , "Description"

Re - Read and posted

if( HowManyStandOffs >0 , lookup"tFTPULL_RTD" "Text1" , if(HowManyStandOffs2 >0 , lookup "rFTPulls_TR" "Text1" , if( HowManyStandOffs3 >0 , lookup "rHMSO_3" "Text1" , Discription )))

We see you have been talking to yourself. Sometimes, just putting in down on paper make one see the problem oneself without help.

Glad you figured it out!

Thanks for the comming back, yes they say that talking to yourself are the first signs of madness, but sometimes it really does help, im still strugling with one small part of it, but I will keep trying, if I get stuck i will post agin.    

Was just going to say that you can run an ExecDQL in a derivation that return the result of the DQL which makes it much easier to structure the code but then I realised that you are useing 6 which definitely doesn't have this option. Hoever you can use OML to do more or less the same.