1)I have booked some flights with Easyjet and Ryanair with a previous passport number and now that passport is no longer valid and I have a new passport, will I have problem ?

2) One of my easyjet booking has a remark that "IMPORTANT: You need to add ID information to your booking" with an "Amend Document Details". I enter it but but my info are all filled, wonder what's the "ID information" they are asking ? One of the flight is to Istanbul.

3) Will airports provide the "re-usable 1 liter plastic bag" required for liquids containers. Is the 100 ml limit for each container or total of all liquids ?

Addition to the above, I don't need a visa to enter Istanbul, wonder what's the ID information Easyjet is asking.

I would not expect airports to provide the 1-litre bag. Though some in the US do, they are a distinct minority. The 100-ml limit is per container; the 1-litre bag may hold a dozen or more small containers of cream/paste/liquid.

Bring your own 1 liter/1 quart plastic bag. A few "nice" airports have them hanging as you enter security. (DFW is one I've seen.) Most do not.

100 ml/3 ounces is the limit for each container. The total limit is however many containers you can fit in one plastic bag.

Thank you.
Anyone have trouble checking in because passport number differs from booking ?
I will bring my old passport along to show proof it's me, should be ok ?

I've used my new passport with no problems - just scanned it at check-in.

I am not sure why you want your old passport, but if it makes you feel better - by any means!

Dayenu,
My bookings are done with my old passport numbers.

In this case, I don't know, and I don't want to tell you to call the 800 number - they may be unhelpful. Is there a US phone number to call the airline?

I would probably go to the airport to ask them if it's OK.