How to configuring a xampp web server for different root directory

windows:
run your xampp control panel
click the button saying config
find document root
replace

DocumentRoot "C:/xampp/htdocs"
Directory "C:/xampp/htdocs"
Those 2 lines

| C:/xampp/htdocs == current location for root |

|change C:/xampp/htdocs with any location you want|

save it
linux:
It can be done in two steps for Ubuntu 14.04 with Xampp 1.8.3-5

DocumentRoot "/opt/lampp/htdocs" and Directory "/opt/lampp/htdocs"

to DocumentRoot "/home/user/Desktop/js" and Directory "/home/user/Desktop/js"

Step 2:- Change the rights of folder (in path and its parent folders to 777) eg via

sudo chmod -R 777 /home/user/Desktop/js