Validation Error

I'm validating my page from my computer so I have no address to give. I put notes in my code using the following format:

    <! -- This is where you pull user data -->

My page does not vilidate because of it. Can you suggest a way to format my notes so that my code validates?

Regards,

Newbie

Error [404]: "character X is the first character of a delimiter but occurred as data"
NOTE: Whenever possible, give the address of the document you were checking.