IIF(ISNOTHING(Fields!Town.Value) OR Fields!Town.Value ="", "",
TRIM(Fields!Town.Value) & vbcrlf) &
IIF(ISNOTHING(Fields!City.Value) OR Fields!City.Value ="", "",
TRIM(Fields!City.Value) & vbcrlf) &
IIF(ISNOTHING(Fields!County.Value) OR Fields!County.Value ="", "",
TRIM(Fields!County.Value) & vbcrlf) &
TRIM(Fields!Post_Code.Value)