public bool isUser(string duz)
{
if (!VistaUtils.isWellFormedDuz(duz))
{
throw new InvalidlyFormedRecordIdException(duz);
}
string arg = "$D(^VA(200," + duz + ",0))";
string response = VistaUtils.getVariableValue(cxn, arg);
return (response == "1");
}