When Were === And !== Introduced?

JQuery :: Underline Links Of Dynamic HTML Introduced In The DOM?

I have a button in my web site "underline links" that changes all thelinks and affects its text decoration to 'underline'. From this pointall the links of the website should be underline. The problem is thatI can only make it work for the current DOM. If I introduce new linksinto the DOM I need to select them specifically to change its textdecoration. Is there something similar to the "live" function injquery? For instance for every links introduced in the DOM I want tocheck if the website is in underline mode. Case its true, the text