Cordova, change name 'www' folder project

I want to copy all the cordoba enviroment in a view of my project, the project name folder is webapp, the problem is, when I try to build with the webapp name, have the error but, when change the name for www, all is ok, is there a way in cordova to change the www name for any other?

P.D. Actually I change the folder name but I want to know if exist the possibility to change the name.

Thanks in advanced!!!