I am examining a sample which is in the salesforce developer site.
In that sample when we click a link it will be redirected to the salesforce login page. If the login successful, then an access token is issued.
I dont want my application to redirect to the salesforce login page. In the existing sample the environment variable is set to,
"https://login.salesforce.com"
What should I do to avoid redirecting to salesforce login page.
What you're describing, sounds like OAuth (just because you mention access-token).
There's a good example of OAuth being used in Salesforce below...
http://wiki.developerforce.com/page/Digging_Deeper_into_OAuth_2.0_at_Salesforce.com