function validar_rut(source, arguments) {
    var rut = arguments.Value; suma = 0; mul = 2; i = 0;
    for (i = rut.length - 3; i >= 0; i--) {
        suma = suma + parseInt(rut.charAt(i)) * mul;
        mul = mul == 7 ? 2 : mul + 1;
    }
    var dvr = '' + (11 - suma % 11);
    if (dvr == '10') dvr = 'K'; else if (dvr == '11') dvr = '0';

    if (rut.charAt(rut.length - 2) != "-" || rut.charAt(rut.length - 1).toUpperCase() != dvr)
        arguments.IsValid = false;
    else
        arguments.IsValid = true;
}