Login to Facebook

I have just downloaded the Facebook for UNity SDK and need to connect my game to a facebook profile. I want to create a prompt asking for the username and password and then login to the respective Facebook account. I am done with creating the prompt for accepting the email and password but I couldn’t find any method to login.
Can anyone suggest me how this can be done ?

Unity SDK consist of an example code, while running this on your machine no use, try

deploying that example in device and check, Facebook login opens attempting for username

and password. then just copy the code from example and modify it according to your project.

Hope you may get some idea from this.