Nested IIF in SSRS Expressions

Question

Is this correct syntax for nested IIF ? Do I need to use Switch ?

...

= IIF ( Fields!FUN.Value.IndexOf ("GU") OR Fields!FUN.Value.IndexOf("HA") 
,IIF (Fields!JobType = "min"   
,IIF(Fields!Van > 0 
, IIF(Fields!Complete.Value > 80
,IIF(LOOKUP(Fields!FUN.Value,Fields!Levelseven.Value,Fields!Over.Value, "Rating")) = 3 and  
LOOKUP(Fields!FUN.Value,Fields!Levelseven.Value,Fields!Over.Value, "Rating"))= 3.5 
, 1000 ,0)))

...

Answer 1

Am I reading that correctly that all of the IIFs must be true in order for the value to be 1000? If so:

=IIF ((Fields!FUN.Value.IndexOf ("GU") OR Fields!FUN.Value.IndexOf("HA"))
    AND
    Fields!JobType = "min"   
    AND Fields!Van > 0 
    AND Fields!Complete.Value > 80
    AND LOOKUP(Fields!FUN.Value,Fields!Levelseven.Value,Fields!Over.Value, "Rating") = 3 
    AND Fields!FUN.Value,Fields!Levelseven.Value,Fields!Over.Value, "Rating" = 3.5 
    , 1000 ,0)