merchasd

I apologize in advance if this message is in the wrong forum.

I will be departing from Singapore to JFK on SQ 26 (SIN-FRA-JFK) on August 1. I've just found out that I need to get to Washington DC (IAD) rather than complete my flight in JFK. I need to do this as cheaply as possible. My flight arrives at 10:50am in JFK, and there is a cheap flight on UAL departing JFK-IAD at 12:43pm. Questions:

1) is there enough time inbetween for me to catch teh 12:43 flight?
2) when I check in at SIN, can they link up my 2 flights and check my luggage all the way through to IAD?

Again, I need to do this as cheaply as possible, so if there would be fees involved let me know.