Hi everyone! This is my first post to the list. I just finished reading the Rails book (totally new to rails and ruby) and am doing a simple guestbook app on my own to get my feet wet. I would like to add validation to the model to make sure that: if a user supplies something for the website_url field, it begins with ''http://'' or ''https://''. If they are not supplying a website_url that''s fine (it''s optional). I also want to make sure they can not supply a website_url without also supplying a name. Can someone please show me how to do this. Thanks! ~ Mike