Does my HTML5 doctype have to be on the VERY first line?

I’ve always wondered whether whitespace before a DOCTYPE matters, but I can’t seem to find any definitive information on the web. People say not to do it, but I can’t see what effect it’s likely to have, or even if the spec says it must be like that. I can’t figure out if it triggers compatibility mode in IE or anything annoying like that.

How to take screenshot of div from a webpage using C# and ASP.NET?

I would like to create dynamic images from html that I’m generating on website. I have code that generates a PSN Trophy Card, ab Xbox LIVE Gamer Card, a Steam Gamer Card, and an Xfire Gamer Card. Each card is put into its own div and built dynamically from server side code. Is there a way to capture a screenshot of a selected div on a webpage using C# and ASP.NET?