How to Create Asynchronous Login Form in ADO.NET

We known that, when we click a submit button on web page then all content of web page post to server. But user want only user name and password post to the server. it is only done by AJAX (Asynchronous JavaScript and XML). In this article we create a login web page using AJAX that check the value of login form on the database server.

There are various steps to create login web page through Ajax:

• Step first, Go Visual studio >> File >> Web application.

• Step second, Design web form with ScriptManager and Update panel:
  
  

• Step third Create Table in Sql sever 2008:
  
  

• Write these code:
  
  Imports System.Data.SqlClient
  Imports System.IO 
  Partial Public Class _Default
      Inherits System.Web.UI.Page 
      Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 
      End Sub 
      Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
          Dim str As String = "Data Source=MCNDESKTOP14;Initial Catalog=studentinfo; uid=sa;pwd=wintellect"
          Dim con As SqlConnection
          con = New SqlConnection(str)
          con.Open() 
          str = "Select * from login where name='" & TextBox1.Text & "' and   Password1 ='" & TextBox2.Text & "';"
          Dim com As New SqlCommand(str, con)
          Dim rd As SqlDataReader = com.ExecuteReader()
          If rd.Read() Then
              Label1.Text = "Vaild user and password"
          Else  
              Label1.Text = "inVaild user and password"
          End If       
  End Sub  
  End Class

Output: