How to know whether I have been served a demand notice

Dear Sirs,

Last year I changed my residence and this change was not intimated to the Income tax department as I did not have any proof of residence.

Further, last year, due to some financial crises, I cold not pay the remaining income tax (over and above the Tax deducted by my employer) and Also did not file my return.

In this regard I have two queries:

1) how to find out whether I have have been served any income tax demand notice?

2) for this year's return, which address should I mention in the return form - my current address or the address which is there in the income tax department record..?

other information

I am salaried person and I am residing in a rented flat without a rent agreement.

Please provide me your valuable advice