php - CakePHP needs to set session for particular folders -

i using cakephp framework. , below problem. www.mysite.com main site , i've created 5-6 different demos of original site different colors , fonts.

so, if login in www.mysite.com/demo1 , open demo www.mysite.com/demo2, shows i'm logged in already.

is there way set session folder wise?

in core.php, few lines before eof, says:

//prefix each application on same server different string, avoid memcache , apc conflicts. $prefix = 'myapp_'; 

have tried different prefix each site?