function CCadena(cadena) {
        cod = strrev(base64_encode(cadena));
        return(cod);
}
function strrev (string) {
    // Reverse a string
    //
    // version: 908.406
    // discuss at: http://phpjs.org/functions/strrev
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   bugfixed by: Onno Marsman
    // *     example 1: strrev('Kevin van Zonneveld');
    // *     returns 1: 'dlevennoZ nav niveK'
    var ret = '', i = 0;

    string += '';
    for ( i = string.length-1; i >= 0; i-- ){
       ret += string.charAt(i);
    }

    return ret;
}

function utf8_encode ( argString ) {
    // Encodes an ISO-8859-1 string to UTF-8
    //
    // version: 908.406
    // discuss at: http://phpjs.org/functions/utf8_encode
    // +   original by: Webtoolkit.info (http://www.webtoolkit.info/)
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: sowberry
    // +    tweaked by: Jack
    // +   bugfixed by: Onno Marsman
    // +   improved by: Yves Sucaet
    // +   bugfixed by: Onno Marsman
    // *     example 1: utf8_encode('Kevin van Zonneveld');
    // *     returns 1: 'Kevin van Zonneveld'
    var string = (argString+'').replace(/\r\n/g, "\n").replace(/\r/g, "\n");

    var utftext = "";
    var start, end;
    var stringl = 0;

    start = end = 0;
    stringl = string.length;
    for (var n = 0; n < stringl; n++) {
        var c1 = string.charCodeAt(n);
        var enc = null;

        if (c1 < 128) {
            end++;
        } else if (c1 > 127 && c1 < 2048) {
            enc = String.fromCharCode((c1 >> 6) | 192) + String.fromCharCode((c1 & 63) | 128);
        } else {
            enc = String.fromCharCode((c1 >> 12) | 224) + String.fromCharCode(((c1 >> 6) & 63) | 128) + String.fromCharCode((c1 & 63) | 128);
        }
        if (enc !== null) {
            if (end > start) {
                utftext += string.substring(start, end);
            }
            utftext += enc;
            start = end = n+1;
        }
    }

    if (end > start) {
        utftext += string.substring(start, string.length);
    }

    return utftext;
}


function base64_encode( data ) {
    // http://kevin.vanzonneveld.net
    // +   original by: Tyler Akins (http://rumkin.com)
    // +   improved by: Bayron Guevara
    // +   improved by: Thunder.m
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   bugfixed by: Pellentesque Malesuada
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // -    depends on: utf8_encode
    // *     example 1: base64_encode('Kevin van Zonneveld');
    // *     returns 1: 'S2V2aW4gdmFuIFpvbm5ldmVsZA=='

    // mozilla has this native
    // - but breaks in 2.0.0.12!
    //if (typeof this.window['atob'] == 'function') {
    //    return atob(data);
    //}

    var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, enc="", tmp_arr = [];

    if (!data) {
        return data;
    }

    data = this.utf8_encode(data+'');

    do { // pack three octets into four hexets
        o1 = data.charCodeAt(i++);
        o2 = data.charCodeAt(i++);
        o3 = data.charCodeAt(i++);

        bits = o1<<16 | o2<<8 | o3;

        h1 = bits>>18 & 0x3f;
        h2 = bits>>12 & 0x3f;
        h3 = bits>>6 & 0x3f;
        h4 = bits & 0x3f;

        // use hexets to index into b64, and append result to encoded string
        tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
    } while (i < data.length);

    enc = tmp_arr.join('');

    switch( data.length % 3 ){
        case 1:
            enc = enc.slice(0, -2) + '==';
        break;
        case 2:
            enc = enc.slice(0, -1) + '=';
        break;
    }

    return enc;
}

function LimpiaCampo(txt1,txt2)
{
        if(txt1.value=='Nombre')
           txt1.value = '';
        if(txt2.value=='Email')
          txt2.value = '';

}

function LlenaCampo(txt1,txt2)
{
   if(!txt1.value)
   {
      txt1.value='Nombre';
      txt1.blur();
   }
   if((!txt2.value)&&(txt1.value=='Nombre'))
   {
      txt2.value='Email';
      txt2.blur();
   }
}

function CampoLleno(txt1,txt2)
{
       if ((txt1.value=="Nombre")||(txt1.value==""))
       {
                alert("Debe ingresar su nombre");
                txt1.value='Nombre';
                txt1.focus();
       }
       else
       {
           if(txt2.value=="")
           {
                alert("Debe ingresar su Email");
                txt2.focus();
           }
       }
}