c# - unauthorized error code when accessing PARSE.COM -

i use code bellow access class book on parse.com

    public void getbook()     {         string requeststring = "https://api.parse.com/1/classes/book";         string applicationid = "my application id";         string restapikey = "my rest api key";          webrequest webrequest = webrequest.create(requeststring);          networkcredential streetcred = new networkcredential(applicationid, restapikey);         webrequest.credentials = streetcred;         webrequest.method = "get";         webrequest.timeout = 100000;         httpwebresponse b = (httpwebresponse)webrequest.getresponse();     } 

this results in 401 unauthorized response. doing wrong ?

i found answer own question !

it appears required key (the second parameter in networkcredentials) should master key , not rest api key.