How to extract JSON value in square brackets?

From a webservice I receive an error message which contains a text in square brackets. How can I extract the ErrorDetail, using the new framework?

{ "ResponseHeader": { "SpecVersion": "1.4", "RequestId": "81FE8EE4-CB17-4D27-86E1-8B0BCBAD3298" }, "Behavior": "ABORT", "ErrorName": "VALIDATION_FAILED", "ErrorMessage": "Request validation failed", "ErrorDetail": [ "ConfigSet: The field ConfigSet is invalid." ] }

dim a() as auto = dictionary.value(“ErrorDetail”)

Passt! Vielen Dank!