AX SSRS : IF Condition with enter ( TRUE )

=First(Fields!VendAddress.Value, "InvoiceHeadPOTmpDS")
+IIF(IsNothing(First(Fields!VendPhone.Value, "InvoiceHeadPOTmpDS"))  OR First(Fields!VendPhone.Value, "InvoiceHeadPOTmpDS") = ""
 ,"", VBCRLF+First(Fields!VendPhone.Value, "InvoiceHeadPOTmpDS") )
 +IIF(IsNothing(First(Fields!VendFax.Value, "InvoiceHeadPOTmpDS"))  OR First(Fields!VendFax.Value, "InvoiceHeadPOTmpDS") = ""
 ,"",VBCRLF+First(Fields!VendFax.Value, "InvoiceHeadPOTmpDS") )