Registering any content to the head
''' Register any content to the head, whatever you pass in will be rendered out.
''' You could for example add a piece of script, a meta data reference or a stylesheet.
''' If the same key is used twice only the first key/script combination will be registered.
''' This ensures that you can call the routine multiple times without registering script multiple times.
Utilities.RegisterHeaderText("YourKey", "<meta http-equiv=""refresh"" content=""600"">")