Form 2119 was discontinued by the Taxpayer Relief Act of 1997. Since that time, you can not defer capital gains on a home by buying one of equal or greater value. What you can do, if you owned and lived in the home for 2 of the 5 years ending on the sale date, is to not have to pay tax on a gain of up to $250,000 (Single), or $500,000 (Married Filing Jointly). Note that if you ever used the home as a rental, then the exclusion does not apply to any gain equal to the depreciation that you claimed or could have claimed.
For further info, see IRS Pubs, 530, 523, and 17
http://www.irs.gov/pub/irs-pdf/p530.pdf
http://www.irs.gov/pub/irs-pdf/p523.pdf
http://www.irs.gov/pub/irs-pdf/p17.pdf