我要成為MVP!!

        Dim Con As New SqlConnection(WebConfigurationManager.ConnectionStrings("myTestConnectionString").ConnectionString.ToString)
        Con.Open()
        Dim Sql As String
        Sql = " Select ID from TableName where id= ' " & UserNameBox.Text & " '"
        Dim SQLcmd As New SqlCommand
        SQLcmd.Connection = Con
        SQLcmd.CommandText = Sql



        If SQLcmd.ExecuteReader.Read Then

            Label5.Text = "此帳號已存在"

        Else
            Label5.Text = "可註冊"


            Con.Close()