Zeppelin, easy enough in Netscape, but Microsoft doesn't even like to mention arch-rival Sun's devlopment. The web site whose URL is given below lists instructions for enabling/disabling java and javascript for both types of browsers. (Note: java and javascript are different things. The former is a full-fledged programming language, the latter just a scripting language. FWIW I enable javascript as needed for trusted sites but I keep java permanently disabled to prevent programmer wannabes from remotely crashing my PC - mostly by incompetence, not maliciousness.)
http://www.cert.org/tech_tips/malicious_code_FAQ.html