Update data from TextBoxes in vb.net to SQL Server

I have a aspx page and created a button to take the values from the textboxes and update the sql tables respectively. However, the updates aren't happening.
Here's my code:

        Try
            'Define database connection
            myconnection_1 = New SqlClient.SqlConnection("server=xxx;user=xxxx; password=rxxx;database = " & DropDownList1.SelectedItem.Value)
            myconnection_1.Open()

            Dim command As String
            Dim command2 As String

            Dim dbcommand As SqlCommand = New SqlCommand(command, myconnection_1)

            'set up an SQL update
            command = "update [user] set FirstName = '" & _
            TextBox1.Text & "', " & " LastName = '" & TextBox2.Text _
            & "', " & " Group = '" & DropDownList2.SelectedItem.Text _
            & "', " & " ProfessionalType = '" & DropDownList3.SelectedItem.Text _
            & " Password = '" & TextBox4.Text _
            & "' where UserName =  '" & TextBox6.Text & "'"

            Dim dbcommand2 As SqlCommand = New SqlCommand(command2, myconnection_1)

            command2 = "update [Professional] set FirstName = '" & _
            TextBox1.Text & "', " & " LastName = '" & TextBox2.Text _
            & "', " & " PatientGroupID = '" & DropDownList2.SelectedItem.Text _
            & "', " & " ProfessionalType = '" & DropDownList3.SelectedItem.Text _
            & "' where UserId =  (select userid from [user] where username = '" & TextBox6.Text & "'"

            'Execute stored procedures
            dbcommand.ExecuteNonQuery()
            dbcommand2.ExecuteNonQuery()

        Catch exceptionObject As Exception
            Label12.Text = ""
        Finally
            myconnection_1.Close()
        End Try
        Label12.Text = "Record has been Updated !"
    End SubStart Free Trial