Get browser version platform details using javascript

<script language="javascript" type="text/javascript">
var StrDummy = navigator.appVersion;
strVersion = StrDummy.substring(0,4);
document.write("<center><table border=1 cellpadding=2><tr><td>");
document.write("<center><b>", navigator.appName,"</b>");
document.write("</center></td></tr><tr><td>");
document.write("<center><table border=1 cellpadding=2><tr>");
document.write("<td>Code Name: </td><td><center>");
document.write("<b>", navigator.appCodeName,"</b></center></td></tr>");
document.write("<tr><td>Version: </td><td><center>");
document.write("<b>",strVersion,"</b></center></td></tr>");
document.write("<tr><td>Platform: </td><td><center>");
document.write("<b>", navigator.platform,"</b></center></td></tr>");
document.write("<tr><td>Pages Viewed: </td><td><center>");
document.write("<b>", history.length," </b></center></td></tr>");
document.write("<tr><td>Color depth: </td><td><center>");
document.write("<b>", window.screen.colorDepth," Bits </b></center></td></tr>");
document.write("<tr><td>Java enabled: </td><td><center><b>");
if (navigator.javaEnabled()){
document.write("Yes !</b></center></td></tr>");
if(navigator.appName != "Microsoft Internet Explorer") {
vartool=java.awt.Toolkit.getDefaultToolkit();
addr=java.net.InetAddress.getLocalHost();
host=addr.getHostName();
ip=addr.getHostAddress();
document.write("<tr><td>Host Name: </td><td><center>");
document.write("<b>",host,"</b></center></td></tr>");
document.write("<tr><td>IP Address: </td><td><center>");
document.write("<b>",ip,"</b></center></td></tr>");
}
}
else document.write("No!</table></center></td></tr>")
document.write("<tr><td>Screen Resolution: </td><td><center>");
document.write("<b>",screen.width," x ",screen.height,"</b></center></td></tr>");
document.write("</table></center>");