Hi! I am Not able to Update database through Datagridview in VB.net Pls help

Question

Hi! I'm trying to Update the database using Datagridview in VB.net. When modify name, address, phone or mobile number and click the update button, other rows(ID) value also changed and same. Pls help me.... thanks in advance  

My code is here:-

Private Sub btnUpdate_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnUpdate.Click

        Dim str As String

        If Not cnn.State = ConnectionState.Open Then

            cnn.Open()

        End If

        If Me.txtID.Text & "" = "" Then

            cmd.Connection = cnn

            cmd.CommandText = "INSERT INTO CLIENT_REGISTER(CLIENTID,NAME,ADDRESS,PHONE,MOBILE) VALUES ('" & Me.txtID.Text & "','" & Me.txtName.Text & "','" & Me.txtAddress.Text & "','" & Me.txtPhone.Text & "','" & Me.txtMobile.Text & "')"

            cmd.ExecuteNonQuery()

        End If

        cmd.Connection = cnn

        str = "UPDATE CLIENT_REGISTER SET NAME='" & Me.txtName.Text & "',ADDRESS='" & Me.txtAddress.Text & "',PHONE='" & Me.txtPhone.Text & "',MOBILE='" & Me.txtMobile.Text & "' WHERE CLIENTID=" & Me.txtID.ReadOnly

        cmd = New OleDbCommand(str, cnn)

        cmd.ExecuteNonQuery()

        RefreshData()

        cnn.Close()

        VEnable()

        Me.btnSave.Enabled = False

        Me.btnEdit.Enabled = False

        Me.btnUpdate.Enabled = False

        Me.btnCancel.Enabled = True

        Me.btnNew.Enabled = True

End Sub