Webhook Not working by vijay

Hi,

I'm trying to create a new Webhook through private API. But it always return

{"errors":{"webhook":"Required parameter missing or invalid"}}

Request URL: https://apikey:password@vijay115.myshopify.com/admin/webhooks.json

Response Header

Status Code: 400 Bad Request
Connection: close
Content-Type: application/json; charset=utf-8
Date: Thu, 04 Dec 2014 12:51:28 GMT
HTTP_X_SHOPIFY_SHOP_API_CALL_LIMIT: 1/40
Server: nginx
Transfer-Encoding: chunked
X-Request-Id: 0d3b14fd-2af5-419f-a6bf-cee202329a88
X-ShardId: 3
X-ShopId: 7098295
X-Shopify-Shop-Api-Call-Limit: 1/40
X-Stats-ApiClientId: 485767
X-Stats-ApiPermissionId: 9134829
X-Stats-UserId: 0
X-XSS-Protection: 1; mode=block; report=/xss-report/0d3b14fd-2af5-419f-a6bf-cee202329a88?source%5Baction%5D=create&source%5Bcontroller%5D= admin%2Fwebhooks&source%5Bsection%5D=admin
status: 400 Bad Request
x-content-type-options: nosniff
x-ua-compatible: chrome=1

{
  "webhook": {
    "topic": "orders/create",
    "address": "http://devtech.com",
    "format": "json"
  }
}

But It's not working. Please any one help to fix this issue.

Regards,

Vijayendran k.