Css
From Bashlinux
Compatibility with all browsers
It happens that some times CSS has no effect on IE, then the solution is to validate the DOCTYPE at the beginning of the code, either HTML, PHP or any other.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
An example of what doesn't work without this tags is the drop-down menus build with pure CSS.
