Checking Client JRE version

Question

This problem is killing me! I need to check what version the
client's JRE is so that they can download and run my app from my web server. They need JRE 1.4.1, and if they don't have it, I want to redirect (potentially) to a page I will create that will inform them of the requirements. (The client will never have admin rights, so can't install it directly from Sun)
I've looked at Jsp and applet solutions but can't get anywhere with it. Does anyone have any ideas on getting around the security issues?
To clarify a bit more, I can have code in the applet to check the
version on the client (jsps will only check the server version) ---
String value = System.getProperty("java.specification.version");
if (value == "1.4.1") {
continue and go to a http page -- but can't redirect from an applet
else {
redirect to an error page or inform the server somehow so I can
redirect the browser.
Any way I can redirect a http page somehow from an applet?
Or set a property in the server which could be read elsewhere...
elpico

Answer 1

use Applet.getAppletContext() to get the AppletContext that represents the page currently displayed by the browser.
then do AppletContext.showDocument(URL�url) to redirect to another page.
AppletContext currentPage = this.getAppletContext();
String value = System.getProperty("java.specification.version");
if (value == "1.4.1")
//OK -> continue.htm
currentPage.showDocument(new URL("http://localhost/continue.htm"));
else {
//ERROR -> error.htm
currentPage.showDocument(new URL("http://localhost/error.htm"));
}thx for the dukes ;),
elchaschab