Tax rebate for Housing Loan

I am an income tax assessee.I and my wife jointly own a house property.My wife is house wife and not earning any income.I have taken a housing loan and paying an EMI from my salary.I am paying Rs.1,40,000 as interest

My query is whether I am eligible to get all interest amount Rs.1,40,000 paid under Section 24  for exemption or only 50 % of interest paid for exemption.My office says that i am eligible to get only 70,000 exemption under Section 24 because I only own 50 % of the property.

Can any expert  enlighten me in this.