my 80% traffic from google has dropped from last 3 days on grotal.com, i have 1.5 million pages indexed with google. pages are still indexed but traffic is zero What is my Site about: my site contains address, contact numbers and operational areas of business (products they deal with) if i m looking for doctors in any city, my site lists all doctors in that city like this grotal.com/Delhi/Doctors-C44/ now click on any result (title) or website My Recent changes: i have opened an individual entry on a subdomain, means, i have created a website for every business man, these subdomains are made at run time, they are more than 500,000 in count, google indexed these subdomains also, but after 5 to 6 days, my results start disappearing from google, then i made some changes, i deleted anchar link from my domain to subdomain and put a javascript link, i put Noindex, Nofollow tag on these subdomain pages, i disallowed all bots in robots.txt for craweling these subdomains. have i done good ? why google stopped showing my result? what is my fault, how can i resolve ? please help me, your help will be appreciated.