Itr-1: how to enter housing loan interest details.

My employer inexplicably did not consider deductions for Housing loan which I had availed last year for the flat, which is now self-occupied. Our company's account department told me to do it while filing tax returns. I am filing Tax Return with ITR-1 using Excel spreadsheet provided on IT Dept's website. Can you please guide me where & how can I enter the home loan interest amount on ITR-1? One of my friend told me to enter loan interest paid in the last financial year as negative amount for head '2. Income from Housing Property' (row no. 42) on the first 'Income Details' tab. Can you please confirm, if that is correct procedure? Thank you.