i had this problem before
if you are using windows 7 open the following folder:
C:\Users\[username]\Documents\Visual Studio 2012\Projects
and there you will see the AjaxAir, AjaxAir (2), AjaxAir (3) along with their "sln" and "suo"
just move them to another location and when you open another website it will be "AjaxAir" again