Unity 5.3 - How do you Grab textfrom InputField in C# Script?

A Quick Note

I have changed the description of what I'm doing so that it is easier to grasp the basic information. I am also a complete beginner at Unity, so please correct me if I go wrong anywhere.

The Topic

The question title is very broad, but the main goal is to get a user to enter their username in the first InputField, their email in the second InputField, and the chat server in the third InputField. The "chat server" is really just a folder consisting of text documents of which are logs.

The Goal

The goal for me is to have a C# script that when a button is pressed, it grabs the information from the 3 InputFields, and write to "D:[ChatServer]\log.txt" a join message, such as:"[Username] contacted at [Email] Joined!"

What I Require

I only require a C# script from you that just has to have the code for grabbing information from 3 InputFields when a button is pressed. It would be very nice of you if you would specify where to put and attach the script as well.

How the Project has been Setup

The project consists of a Canvas first being created using the UI within the unity editor. The first InputField created was the username, the second being the email, and the third being the chat server. Then a button was created, and attached to the button is a script that detects when the button has been pressed.

The Project's Looks

I have uploaded some images for you to look at, for reference. Image 1 - The Hierarchy: http://prntscr.com/bejy4n Image 2 - The First InputField [Username] : http://prntscr.com/bejyea Image 3 - The Second InputField [Email] : http://prntscr.com/bejyks Image 4 - The Third InputField [ChatServer] : http://prntscr.com/bejysr

My Apologies and Thanks

I thank you for your reply, as it might provide some light to my problem, and if you fixed the problem, my congratulations and thanks for you being a dedicated Unity user, and helping others just as you would like them to help you, and giving complete beginners at Unity a helping hand, even when their message doesn't quite make sense.

My apologies to all who think of my question to be very precise and demanding on the result, I am sorry for being rude, as I do not wish for myself to come off rude or demanding. I also apologize for my question coming off as some sort of "License Agreement" with sections, as I wouldn't like to have a simple question I am going to answer look like a license agreement.