Import JEE Web project on Netbeans

I want to import an existing Java Web project . But soon as I specify the 'Existing Sources and libraries', I get the error :

" Web pages folder overlaps Project folder"

Then I specify the web folder as a folder i created named "web" that contains the WEB-INF repository . I get this error :

"The specified java sources folder contains class files .Because IDE generates compiled class files in the 'build' folder . Do you want to delete those class files"

Any hint or help would be highly apreciated.