how to get the path prefix ?

Hi,

I started my rails application using mongrel with --prefix=/myapp; I have a javascript file where it makes an ajax call to '/get_pics'; But this fails when I use --prefix option;

is there a method in rails which will return the path prefix (in this case its: myapp); so that I can assign it to a javascript variable 'PATH' in my layout and then make an ajax call to ( PATH + '/get_pics') ?

OR Is there any other way to solve this problem ?