function getCAPICOMObject(type) {
	var obj = null;		
	if (CAPICOM_OBJECTS[type]) {
		return CAPICOM_OBJECTS[type];
	}
	if (undefined != window.ActiveXObject) {
		obj = new ActiveXObject("CAPICOM." + type);
		if (obj) {
			CAPICOM_OBJECTS[type] = obj;
		}
	}
	return obj;
}

var MyStore = getCAPICOMObject("Store");
MyStore.Open(CAPICOM_CURRENT_USER_STORE, CAPICOM_MY_STORE, CAPICOM_STORE_OPEN_READ_ONLY);
var Certificates = MyStore.Certificates;
var selectedCertificates = Certificates.Select("Список сертификатов", "Выберите сертификат для подписи документа:");
user_certificate = selectedCertificates.Item(1);

var SigData = getCAPICOMObject("SignedData");
var Signer = getCAPICOMObject("Signer");
Signer.Certificate = user_certificate;

Signer.Options = 2;
SigData.Content = 'KOEzm6ejA7UC44FYlxDmCJ1ERUsp+H61yDABUEKyqPg=';

var signature = SigData.Sign(Signer, true);