tbody tr:nth-child(2n) td, tbody tr.even td {background: none repeat scroll 0 0 transparent;padding: 0;border-spacing: 0}
img#captcha{margin-left: 20%}
table#vista{width: 80%}
#background{position: fixed;z-index: -1;top: 0;left: 0;width: 100%;height: 100%}
fieldset#formulario{margin-right: auto;margin-left: auto;width: 30%;margin-top: 20%;}
input.uno{display:block;margin: auto}
label{font-weight: bolder; color:black}
input#txtcaptcha{display:block;}

td.imagen_captchaxx               
{
    text-align: left;
}

td.texto_captcha               
{
    text-align: left;
}