International Flight - 2 airlines.. Transfer question

[heathrow42]

I didn't know where else to look.. I thought someone here might be able to answer my question.


We are booking a flight to Paris (DLRP!!) The cheapest flight is on Orbitz it has us going from Newark, NJ to London on Virgin Air - and then from London to Paris on BMI

My question is.. when we get to London, do we have to go through customs, get our luggage - check in on the other airline and go through security again? How does this work?

Thanks in advance,
--heather