linking login page with sql server

Question

 I have created a login page in asp.net and now i want to connect that page with sql server .

I have created a database named xyz..

I created Table for Login Page.

But Problem is I dont Know how to link it with database.....

 

 

This is the source code for my login page::

 

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Register.aspx.cs" Inherits="_Default" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">

</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">

<!-- breadcrumbs -->

<div class="breadcrumbs">

<div class="container">

<ol class="breadcrumb breadcrumb1 animated wow slideInLeft" data-wow-delay=".5s">

<li><a href="Home1.aspx"><span class="glyphicon glyphicon-home" aria-hidden="true"></span>Home</a></li>

<li class="active">Register Page</li>

</ol>

</div>

</div>

<!-- //breadcrumbs -->

<!-- register -->

<div class="register">

<div class="container">

<h3 class="animated wow zoomIn" data-wow-delay=".5s">Register Here</h3>

<p class="est animated wow zoomIn" data-wow-delay=".5s">For All New User's to this Website Please Register Here</p>

<div class="login-form-grids">

<h5 class="animated wow slideInUp" data-wow-delay=".5s">profile information</h5>

<form class="animated wow slideInUp" data-wow-delay=".5s">

<input type="text" placeholder="First Name..." required=" " id="txtfirstname" >

<input type="text" placeholder="Last Name..." required=" " id="txtlastname">

</form>

<div class="register-check-box animated wow slideInUp" data-wow-delay=".5s">

<div class="check">

<label class="checkbox"><input type="checkbox" name="checkbox"><i> </i>Subscribe to Newsletter</label>

</div>

</div>

<h6 class="animated wow slideInUp" data-wow-delay=".5s">Login information</h6>

<form class="animated wow slideInUp" data-wow-delay=".5s">

<input type="email" placeholder="Email Address" required=" " id="txtemailid" >

<input type="password" placeholder="Password" required=" " id="txtpass">

<input type="password" placeholder="Password Confirmation" required=" " id="txtconfpass" >

<div class="register-check-box">

<div class="check">

<label class="checkbox"><input type="checkbox" name="checkbox"><i> </i>I accept the terms and conditions</label>

</div>

</div>

<input type="submit" value="Register" id="btnregister">

</form>

</div>

<div class="register-home animated wow slideInUp" data-wow-delay=".5s">

<a href="Home1.aspx">Home</a>

</div>

</div>

</div>

<!-- //register -->

</asp:Content>