How to send request as a header

Question

I need to send a request to a payment switch with the following parameters in asp.net  C# and receive an json response, any idea how

 

Sample Request (JSON)

GET
https://stageserv.interswitchng.com/test_paydirect/api/v1/gettransaction.json?productid=21&transactionreference=8421941122&amount=300000 HTTP/1.1
UserAgent: Mozilla/4.0 (compatible; MSIE 6.0; MS Web Services Client Protocol 4.0.30319.239)
Hash: F6FF2E22F99D93DDDA52D71811FD92B3A71FA1968A66216E0D310DAD

 

 

Sample Response (JSON)

HTTP/1.0 200 OK
Date: Tue, 30 Oct 2012 16:12:17 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 333

{"Amount":300000,"CardNumber":"6055","MerchantReference":"8421941122","PaymentReference":"ZIB|WEB|VNA|15-10-2012|015933", "RetrievalReferenceNumber":"000000538268", "LeadBankCbnCode":null, "LeadBankName":null, "SplitAccounts[],"TransactionDate":"2012-10-15T11:07:54.547","ResponseCode":"00","ResponseDescription":"Approved Successful"}

 

 Please help