Simple Application in VB.Net

Public Class Form1
    Dim sqlconnection As New System.Data.SqlClient.SqlConnection
    Dim sqlCommand As New System.Data.SqlClient.SqlCommand
    Dim sqlDataAdapter As New System.Data.SqlClient.SqlDataAdapter
    Dim cmdBuilder As System.Data.SqlClient.SqlCommandBuilder
    Dim dsDataset As New DataSet
    Dim cmCurrency As CurrencyManager
    Dim LastUID As Integer = 0
    Dim newrow As DataRow

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim dt As New DataTable
        sqlconnection.ConnectionString = "Data Source=Manoj;Initial Catalog=imported_data;User ID=sa;Password=sa"
        sqlCommand.CommandText = "select * from mstcompanies"
        sqlCommand.Connection = sqlconnection
        sqlDataAdapter.SelectCommand = sqlCommand

        cmdBuilder = New System.Data.SqlClient.SqlCommandBuilder(sqlDataAdapter)
        sqlDataAdapter.Fill(dt)
        DataGridView1.DataSource = dt

        txtUID.Text = dt.Rows(0).Item(0)
        txtName.Text = dt.Rows(0).Item(2)
        txtAddress.Text = dt.Rows(0).Item(4)
        txtCity.Text = dt.Rows(0).Item(5)

        dsDataset.Tables.Add(dt)
        dsDataset.Tables(0).TableName = "mstcompanies"
        sqlDataAdapter.TableMappings.Add(New System.Data.Common.DataTableMapping("Table", "mstCompanies"))

        Call bindFields(dt)
        cmCurrency = BindingContext(DataGridView1.DataSource, DataGridView1.DataMember)
    End Sub
    Public Function bindFields(ByVal dtSrc As DataTable)
        txtUID.DataBindings.Add("Text", dtSrc, "UID")
        txtName.DataBindings.Add("Text", dtSrc, "Name")
        txtAddress.DataBindings.Add("Text", dtSrc, "Address")
        txtCity.DataBindings.Add("Text", dtSrc, "City")
    End Function

    Private Sub btnNew_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNew.Click
        txtUID.Text = ""
        txtName.Text = ""
        txtAddress.Text = ""
        txtCity.Text = ""

        newrow = dsDataset.Tables("mstCompanies").NewRow
        LastUID = dsDataset.Tables("mstcompanies").Rows(dsDataset.Tables("mstcompanies").Rows.Count - 1).Item("UID")
        txtUID.Text = LastUID + 1
    End Sub

    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        With dsDataset.Tables("mstcompanies")

            If txtName.Text = "" Then
                MsgBox("Please Enter Company Name")
                Exit Sub
            End If

            dsDataset.Tables("mstcompanies").Rows.Add(newrow)
            newrow.Item("UID") = txtUID.Text + 1
            newrow.Item("Name") = txtName.Text
            newrow.Item("Address") = txtAddress.Text
            newrow.Item("City") = txtCity.Text

            sqlDataAdapter.Update(dsDataset)
            MsgBox("Record Save Successfully.")


        End With
    End Sub

    Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click
        cmCurrency.RemoveAt(cmCurrency.Position)
        sqlDataAdapter.Update(dsDataset)
        MsgBox("Record Delete Successfully.")
    End Sub

    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        dsDataset.Tables("mstCompanies").Rows(cmCurrency.Position).Item("Name") = txtName.Text
        dsDataset.Tables("mstCompanies").Rows(cmCurrency.Position).Item("Address") = txtAddress.Text
        dsDataset.Tables("mstCompanies").Rows(cmCurrency.Position).Item("City") = txtCity.Text
        sqlDataAdapter.Update(dsDataset)
        MsgBox("Record Update Successfully.")
    End Sub

    Private Sub btnPrevious_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPrevious.Click
        cmCurrency.Position = cmCurrency.Position - 1

    End Sub

    Private Sub btnNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNext.Click
        cmCurrency.Position = cmCurrency.Position + 1
    End Sub

    Private Sub btnFirst_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFirst.Click
        cmCurrency.Position = 0
    End Sub

    Private Sub btnLast_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLast.Click
        cmCurrency.Position = cmCurrency.Count
    End Sub
End Class