Currently Being ModeratedDec 6, 2012 8:32 AM (in response to missnelsonismissing)
I think you are confusing RAM memory with the Hard Drive/SSD Size.
I am answering this with over 20 years PC experience and am currently sorting out a friends Windows 7 Laptop (grrr)
You need click on the Apple top left, select About this Mac and Storage.
Your old Pro will probably be a Hard Drive of XXXGB (e.g. 500GB) whereas your Air will be a SSD/Flash Storage of YYYGB (e.g. 256GB).
Now, I would move all your personal data/files off the old Pro (Finder, Username sub-directories) onto at least one external drive (Hard disk, USB memory stick, etc). This includes Documents, Movies, Music, Pictures so that all that is left on the old Pro is the actual Mac and purchased software.
Then the Pro should have less data to migrate across to your Air. This is a bit long winded but you have to ensure the source data is less that the destination data.