Detect if Java is enabled from HTMLTag(s): Environment
For a Javascript solution, check this How-to
<HTML><HEAD></HEAD><BODY> <APPLET CODE="MyApplet.class" NAME="myApplet" HEIGHT=400 WIDTH=400 ALT="Oups! You don't have JAVA enabled"> <A HREF="nojava.html">Oups! You don't have JAVA enabled, click here.</A> </APPLET> </BODY></HTML>