Attach curves
 

http://img232.imageshack.us/img232/4...estion1zc1.jpg

How do I round these two corners? I am using Attach Curves with blend option to round the other two corners, but after that I can only use it 1 more time, which means after I use Attach Curves again, I will have 3 rounded corners but there's no more curves to attach... please help me :)

First thing to do is ensure the curve directions on all of the curves are correct, if not reverse them they should all flow the same way... U V . . . then U V . . . etc...

Once you get the 3 corners right, do a open/close curve. that should sort it.

Thanks!