$(document).ready(function()
    {
        $('#region_btnSave').click(function ()
        {
            var txtHValue = $("#region_tabVersao_N_txtH").val();
            var emailAddressValue = $("#region_tabVersao_N_txtM").val();
            if (emailAddressValue == '' || txtHValue == '') {
                $("#region_tabVersao_N_txtH").after('<span class="error">Campo Obrigadorio</span>',null);
                    return false;
            }
            else {
                //not all text fields are valid
                $("#region_tabVersao_N_txtH").after('', null);
            }

    });
    });

<td>
                                                                 <asp:TextBox ID="txtH" runat="server" MaxLength="3" Width="40" />
<span class="error"></span>
</td>