Error in getRequestToken and getAccessToken

[Jaydeep]

Hi,
I am developing client and server model which shows workflow of oAuth
protocol.
But, I am getting following error message while calling
getRequestToken("http://localhost/server/serverlogin.php?
oauth_callback='http://localhost/client/callback.php')

Fatal error: Uncaught exception 'OAuthException' with message 'Invalid
auth/bad request (got a 403, expected HTTP/1.1 20X or a redirect)' in /
var/www/html/oAuth_Working_Model/btpCode/client/index.php:21 Stack
trace: #0 /var/www/html/oAuth_Working_Model/btpCode/client/
index.php(21): OAuth->getRequestToken('http://localhos...') #1 {main}
thrown in /var/www/html/oAuth_Working_Model/btpCode/client/index.php
on line 21

Same error is getting thrown while calling getAccessToken function.

please help me.