how to add a related table values in call a script function

[BHUVANESH]

how to add related table values in call a script function 

my function parameter is

CONCATENATE("{",

"""" & ID & """" ":" & """" & [ID] & """" ","
"""" & Invoice No & """" ":" & """" & [Invoice No] & """" ","

"""" & Dates & """" ":" & """" &[Date]& """" ","

"""" & Client & """" ":" & """" & [Client] & """" ","

"""" & Items & """" ":" & """" & [Related invoice items] & """" ","

"""" & Total & """" ":" & """" & [Total] & """" ","

"""" & Notes & """" ":" & """" & [Notes] & """" ","

"""" & User & """" ":" & """" & [User] & """" ","

"""" & Timestamp & """" ":" & """" & [Timestamp] & """" ,

"}"

)

 how to I sent the related invoice item details.
that table contain Amount ,qty column 
how to I sent the this values to the function parameter