Systems and techniques for generating a markup language document that has content to be conditionally display are disclosed. The markup language document includes JavaScript code and one or more comment tags indicating that content between the one or more comment tags is not to be processed for display by a client computer. The markup language document further defines a variable to hold a value. When the variable is a first value, at least one of the comment tags is ignored as a comment tag such that the content between the comment tags is processed for display. When the variable is a second value, the one or more comment tags are processed normally, such that the content between the comment tags is not displayed.