Here is how I did it. It works great. Thanks for help.
//construct the json
Var pa_request as New JSONItem
Var passport As New JSONItem
passport.Value(“accesskey”) = TfKey.Value //Gets the text input from the textbox
passport.Value(“account”) = TfAcct.Value //Gets the text input from the textbox
passport.Value(“password”) = “”
passport.Value(“requestkey”) = “Test3”
passport.Value(“username”) = “”
Var items As New JSONItem
Var mypart as New JSONItem
mypart.value(“id”) = “TestId”
mypart.Value(“itemnumber”) = TfPart.Value //Gets the text input from the textbox
mypart.Value(“quantity”) = 1
mypart.Value(“reference”) = “TestRef”
mypart.Value(“wh”) = 1
items.Add(mypart)
// Add to the pa_request object
pa_request.Value(“items”) = items
pa_request.Value(“passport”) = passport