Retrieving error code from RequestAgentLogin response

[Alyw]

I'm developing an agent desktop using PSDK 8.5 in C#.net. When I try to registering an agent, I received response from RequestAgentLogin as below:

'EventError' ('52')
message attributes:
AttributeEventSequenceNumber [long] = 4616
AttributeCustomerID [str] = "Resources"
Time            = ComplexClass(TimeStamp):
  AttributeTimeinuSecs [int] = 548000
  AttributeTimeinSecs [int] = 1435627601
[color=blue]AttributeErrorCode [int] = 620
[/color]AttributeThisDN [str] = "6145"
AttributeReferenceID [int] = 2

How can I get the error value as I highlighted in blue? I also found that error 620 is equivalent to Errors.TERR_ASAI_INCS_AGT_ST.