How can i get the result of translator api?

Hi, i want to get an access token. but i can't.

I requested for Bing translate API address with the parameters by useing advanced Rest client which i can download at chrom web store.

these are  API address and parameters which i put in the advanced Rest client.

api address: http://api.microsofttranslator.com/V2/Ajax.svc/Translate

parameter(using get method)

appId : saTranslator

from : en

to : fr

text : hello

parameter(using post method)

access_token : :***************************

but i can't get the result.

i got the response like this.

response : "ArgumentOutOfRangeException: 'to' must be a valid language\u000d\u000aParameter name: to : ID=5217.V2_Json.Translate.2B7B239A"

what's the problem? is my request wrong?