JScript was introduced with IE 3 (1996)<p>Dynamic HTML (modifying the page with javascript) was introduced with IE 4 (1997)<p>iframes were introduced with HTML 4 (1998) I think.<p>XMLHttpRequest was introduced with IE 5 (1999)<p>So 1998 era, maybe, but Javascript had a reputation as being slow and buggy.  Flash, Java applets, and even active X were more acceptable technology at the time.<p>(Not trying to dismiss Netscape in my timeline -- I wrote it with respect to Microsoft implementing it.)