Using associative array in soapUI step script

Hi All,

I just need to send an associative array as part of an input to AMF call.

In the AMF Request step I have:
- property called "input"
- the following script:

header['date'] = '123';
header['time'] = '987';
header['etc'] = 'abc';

body['data'] = 'abcdeds';
body['key'] = '123';

parameters["input"] = [header, body];

The test case fails with error message:
-> SubmitException: com.eviware.soapui.model.iface.Request$SubmitException: AMF request is not initialised properly !

If I just put the following code, it works fine

parameters["input"] = "hello";

I know that I'm doing something wrong around defining the associative array, but after few hours of searching the web... here I am

Samples, or any other help would be appreciated.