Let’s see the brief demonstration of using default login control.

Step 1: first open visual studio and select new project from file menu and then click on website.

Step 2: After successful creating new project then click on toolbox from left pane, drag login control from left pane and drop it on your web page.

Step 3: after dropping it on your web page it will appear as follows

Step 4: If you want to change formatting of login control then click login task button and select Auto Formatting

After selecting auto formatting option from login task then another formatting window appears where you have more choice to select login control formatting.

After choosing the appropriate formatting then you can set properties of login control such as error messages, login control header text etc. 

Now to validate user double click on login control and write the following code on Login1_Authenticate1 event

  ///<summary>
    /// To check login user is authenticated or not 
    ///</summary>
  
      privateboolAuthenticateUser(stringusername, stringpassword)
    {
        boolboolcheckReturn=false;
        SqlConnectioncon= new SqlConnection(ConnectionString.ConnString());
        SqlCommandcmd=newSqlCommand("select username from tbllogin where username ='"+username+"' and password ='"+password+"'", con);
        //// use to explore Sqlcommand used text query
        cmd.CommandType=System.Data.CommandType.Text;
        /// connection open 
        con.Open();
        /// ExecuteScalar() method reaturn object if there record found then return first row of first cell value 
        objectobj=cmd.ExecuteScalar();
  
        /// check user is authenticate or not 
        if (obj!=null)
         {
            /// return true if user authenticate
            returnboolcheckReturn=true;
         }
        else
         {
            /// return false if user are not  authenticate
            returnboolcheckReturn=false;
         }
        
  
  
    }
    ///<summary>
    ///   authenticate event when click on login button  
    ///</summary>
   
    protectedvoidLogin1_Authenticate1(objectsender, AuthenticateEventArgse)
    {
        boolcheckAuthentication=false;
        /// call AuthenticateUser method to validate user  
        checkAuthentication=AuthenticateUser(Login1.UserName, Login1.Password);
        e.Authenticated=checkAuthentication;
        if (checkAuthentication)
         {
            // successful login with full authentication 
            /// if user are authenticated then anoter home.aspx page are opened  
            Response.Redirect("home.aspx");
         }
       
    }

After run the program if you click on Log In button then following required field validator are displays.

If you enter wrong Username or Password then following message are displays.