Hi,
Write following on Startup
var vDate = APPLICATION.getInfo().dateNowInternalFormat;
var vDay = Convert.subString(APPLICATION.getInfo().dateNowInternalFormat, 6,8);
vMonth = Convert.subString(APPLICATION.getInfo().dateNowInternalFormat, 4,6);
vYear = Convert.subString(APPLICATION.getInfo().dateNowInternalFormat, 0,4);
Then SetSelected in DropDownUsing month & year above.