hide email and other sensitive information from spam harvesters

Often we have to display email addresses and other contact information on our pages. For example providing a mailto link etc. However, along with the intended users, some other persons/bots are also interested in getting those email IDs for sending spams. For this, spammers use special bots for harvesting email/contact info from the web. In this post, I will show a method using javascript and any server side language by which we can easily protect such important information.