Create a login system using config file using .net web aplication

LoginPage.aspx page

This below page used for the Textbox and password field

 <h3 class="bg-primary text-white">Login Here</h3>
      <table class="table table-hover">
     <tr><td> <asp:TextBox ID="TextBox1" runat="server" placeholder="User Name"></asp:TextBox> </td></tr>
      <tr><td> <asp:TextBox ID="TextBox2" runat="server" placeholder="Password" TextMode="Password"></asp:TextBox> </td></tr>
       <tr><td> <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" /> </td></tr>
      </table>

web config file

<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.6.1"/>
    <httpRuntime targetFramework="4.6.1"/>

<!-- THIS IS THE MAIN CODE WHICH IS MOST IMPORTANT -->
    <authentication mode="Forms">
      <forms defaultUrl="~/TravelDetailsInsert.aspx" loginUrl="~/LoginPage.aspx">
        <credentials passwordFormat="Clear">
          <user name="admin" password="admin"/>
          <user name="rumman" password="rumman"/>
        </credentials>
      </forms>
    </authentication>

<!-- END OF FOCUS HERE -->

  </system.web>

<!-- THE BELOW CODE IS IMPORTNT IF YOU WANT TO USE THE VALIDATION CONTROL -->
  <appSettings>
    <add key="ValidationSettings:UnObtrusiveValidationMode" value="None"/>    
  </appSettings>

<!--  THE BELOW CODE IS USED TO CONNECT WITH THE DATA BASE SQL SERVER-->
  <connectionStrings>
    <add name="constring" connectionString="Data Source = intvmsql01; Initial Catalog = DB02TEST01; User ID= pj02test01; password=tcstvm;"/>
  </connectionStrings>

  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs"
        type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.8.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
        warningLevel="4" compilerOptions="/langversion:default /nowarn:1659;1699;1701"/>
      <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb"
        type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.8.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
        warningLevel="4" compilerOptions="/langversion:default /nowarn:41008 /define:_MYTYPE=\"Web\" /optionInfer+"/>
    </compilers>
  </system.codedom>

</configuration>

file name: LoginPage.aspx.cs

The below using System.Web.Security; is important to execute the below code

using System.Web.Security;

protected void Button1_Click(object sender, EventArgs e)
        {

            if(FormsAuthentication.Authenticate(TextBox1.Text, TextBox2.Text))
            {
                FormsAuthentication.RedirectFromLoginPage(TextBox1.Text, false);
            }
            else
            {
                Label3.Text = "Invalid Credentials entered.";
            }
            //if (TextBox1.Text == "admin" && TextBox2.Text == "password")
            //{
            //    Response.Redirect("TravelDetailsInsert.aspx");
            //    Label3.Text = Convert.ToString("Successfully Login");
            //} 
            //else
            //{
            //    Response.Write("<script> alert('User Name or Password is wrong') </script>");
            //    Label3.Text = Convert.ToString("UnSuccessfully Login");
            //}
        }