We plan to take an early morning train from Prague to Budapest on 9/21/2011. I have been looking at this website www.cd.cz. to purchase 2 tickets. I would also like to buy seat reservations. You can actually see the available seats and select them .There does not seem to be an option to buy them together. Also, I have to first register in order to purchase tickets. When I input my American phone number with area code, I keep on getting an error. I have tried all sorts of ways using the US country code of 1. Please help.

If possible, I suggest you buy your tickets in Prague instead of buying them now. (This how I bought my Prague-Vienna train ticket when I visited.) If you will have any time in Prague before you leave, just go to the station while you are there and buy tickets a day or two in advance. 9/21 is a Wednesday so I highly doubt it's a busy day and will sell out days in advance, unless there's some big event going on in Prague then.

Well, I don't have an experience with booking with CD from abroad, so I have no idea how it works. Anyway, there should be no problem to buy the tickets in Prague as Andrew suggest yet the price will be most probably higher than when buying online.

Check the prices on low-fare airlines. Unless taking an overnight sleeper train, a quick flight may be better.

Flying for this simple journey will take four hours of taxis or buses to remote airpots miles outside the cities they serve, stressful airport security checks and an unnecessary high-carbon fight. So unless you're in a mad rush on some sort of business trip, stick with the relaxing centre to centre train ride.

You can easily buy a ticket at the station, there's always places available, and the full price is around 40 euros in 2nd class as I recall, perhaps 60 in 1st class.

However, it's cheaper to book in advance, from 19 euros one-way at www.cd.cz/eshop

Yes, you need to regsiter, but who is going to call you? So the phone number you use doesn't matter. So put whatever it takes to get yourself registered, even a check number off the internet if necessary. I get lots of emails reporting success buying at the CD (Czech railways) eshop, with lots of 19 euro ticket availbility, although no-one has yet reported any problem enteing phone numbers.

Thanks for the responses. I was actually able to navigate through www.cd.cz/eshop and purchase the tickets and seat reservations. They were around $27/ticket. I was able to email my questions through the website and worked through it. I actually did not have to enter a phone number. So it worked out fine and I saved some money.