What's the Name of That Book??? discussion

So I read this book when I was around probably 9, 11 years back now. What I remember was the main character's were two kids, I believe one male and one female.

They found this book or something with an ancient language that they found allowed them to control the elements, basically magic.

One specific scene I remember was they were on top of a building and they basically hardened air and were able to walk on it.

I believe it was a series (that I never got to finish! :O). Any help would be greatly appreciated.

EDIT: I'm fairly sure it was written in either the 80s or 90s.

So You Want to Be a Wizard possibly?

Ann aka Iftcan wrote: "So You Want to Be a Wizard possibly?"

I do actually believe that was it! Thank you so much! Now I can show my fiance this book, and who knows, maybe my daughter will like it in a couple years. I know I enjoyed it.

Yeah, the air-walking sounds very familiar.