How to create login form with multi users and permissions in VB.net using Sql database[with Source code]

 Imports System.Data.SqlClient

Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim conn As New SqlConnection("Data source=.;initial catalog=login3;integrated security=true")

        If conn.State = ConnectionState.Closed Then

            conn.Open()

        End If

        Dim cmd As New SqlCommand("Select * from Admin where username='admin' and password=@password", conn)

        cmd.Parameters.AddWithValue("password", TextBox1.Text)

        Dim myreader As SqlDataReader = cmd.ExecuteReader

        If (myreader.Read()) Then

            username_v = myreader("username")

            Form2.Show()

            Me.Hide()

        Else

            MsgBox("Error Password")

        End If

    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

        Me.Close()

    End Sub

    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click

        Dim conn As New SqlConnection("Data source=.;initial catalog=login3;integrated security=true")

        If conn.State = ConnectionState.Closed Then

            conn.Open()

        End If

        Dim cmd As New SqlCommand("Select * from users where username=@username and password=@password", conn)

        cmd.Parameters.AddWithValue("username", TextBox3.Text)

        cmd.Parameters.AddWithValue("password", TextBox2.Text)

        Dim myreader As SqlDataReader = cmd.ExecuteReader

        If (myreader.Read()) Then

            username_v = myreader("username")

            If Not myreader.IsDBNull(myreader.GetOrdinal("insert")) Then

                CheckBox1.Checked = myreader("insert")

            End If

            If Not myreader.IsDBNull(myreader.GetOrdinal("update")) Then

                CheckBox2.Checked = myreader("update")

            End If

            If Not myreader.IsDBNull(myreader.GetOrdinal("delete")) Then

                CheckBox3.Checked = myreader("delete")

            End If

            If CheckBox1.Checked = False Then

                Form2.Button1.Visible = False

            End If

            If CheckBox2.Checked = False Then

                Form2.Button2.Visible = False

            End If

            If CheckBox3.Checked = False Then

                Form2.Button3.Visible = False

            End If

            Form2.Show()

                Me.Hide()

            Else

                MsgBox("Error Password")

        End If

    End Sub

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

        Me.Close()

    End Sub

End Class

ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ

Public Class Form2

    Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        Label1.Text = "Welcome, " & username_v

    End Sub

End Class

ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ

Module Module1

    Public username_v As String

End Module