Sorry, I forgot to mention that. It is POST request. I convert, actionscript model object which has to be passed as an argument to the service, into XML form and then I convert that XML into byte array using ByteArray class. Then I call post function of the httpclient class with 3 arguments i.e uri, byte array data and contenttype.

post(uri, byteArrayData, contentType)

here, contentType is "application/xml" and uri is the url of the rest service.