<!--
    function ark_validar( form ) {
      var error = false;
      var j     = -1;
      var chain = "";
      for ( var i = 0; i < form.elements.length; i++ ) {
        if ( form.elements[i].title && ( form.elements[i].value == "" || ( form.elements[i].type == "checkbox" && !form.elements[i].checked ) ) ) {
          if ( j < 0 ) {
            j   = i;
          }
          chain = chain + "· " + form.elements[i].title + "\n";
          error = true;
        }
      }
      if ( error ) {
        alert( "El o los siguientes campos no pueden quedar incompletos antes de proceder:\n\n" + chain );
        form.elements[j].focus();
        return false;
      }
      else {
        for ( var i = 0; i < form.elements.length; i++ ) {
          if ( form.elements[i].title && form.elements[i].name == "email" ) {
            if ( !ark_emailValido( form.elements[i].value ) ) {
              alert( "Email inválido!" );
              form.elements[i].focus();
              return false;
            }
            else {
              return true;
            }
          }
        }
      }
    }

    function ark_emailValido( email ) {
      return email.match(/\b(^(\S+@).+((\.com)|(\.net)|(\.info)|(\.edu)|(\.gov)|(\.org)|(\.info)|(\.biz)|(\.tv)|(\.tk)|(\.es)|(\.cl)|(\.ch)|(\..{2,2}))$)\b/gi);
    }

    function ark_validarBusqueda() {
      var form		= document.getElementById("buscar");
      if ( form && form.s.value != "" )
        return true;
      else
        return false;
    }

    function ark_cambiarModo( id ) {
      ark_mostrar( "listado","none" );
      ark_mostrar( "espera", "" );
      for ( var i = 0; i <= cant_mods; i++ ) {
        m = document.getElementById("mod"+i);
        a = m.getElementsByTagName("a")[0];
        if ( m && i != id )
          a.className   = "";
      }
      m = document.getElementById("mod"+id);
      a = m.getElementsByTagName("a")[0];
      a.className  = "activo";
      ajax( rel + "inc/_ajax-avisos.php?elem=mod&valor=" + id );
    }

    function ark_marcarCategoria( id ) {
      ark_mostrar( "listado", "none" );
      ark_mostrar( "espera",  "" );
      c			= document.getElementById("cat"+id);
      if ( c ) {
        if ( c.className == "activo" )
          c.className	= "";
        else
          c.className	= "activo";
      }
      ajax( rel + "inc/_ajax-avisos.php?elem=cat&valor=" + id );
    }

    function ark_mostrar( elem, action ) {
      document.getElementById( elem ).style.display  = action;
    }

    function ark_limpiar( formulario ) {
      var form	= document.getElementById( formulario );
      if ( form )
        form.reset();
    }

    function ark_caracteres( nombre, limite ) {
      var campo			= document.getElementById(nombre);
      var cont			= document.getElementById('caracteres_'+nombre);
      if ( campo.value.length > limite )
        campo.value		= campo.value.substring( 0, limite );
      if ( cont )
        cont.innerHTML		= limite - campo.value.length;
    }
-->