/* browser_chk() */
/* JavaScript code for client browser check */
/* Alert user if the browser has not been tested or higher version is required  */


function browser_chk() {
     // convert all characters to lowercase to simplify testing
     var agt=navigator.userAgent.toLowerCase();

     // *** BROWSER VERSION ***
     // Note: On IE5, these return 4, so use is_ie5up to detect IE5.
     var is_major = parseInt(navigator.appVersion);
     var is_minor = parseFloat(navigator.appVersion);

     // Note: Opera and WebTV spoof Navigator.  We do strict client detection.
     // If you want to allow spoofing, take out the tests for opera and webtv.
     var is_nav  = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1)
                 && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1)
                 && (agt.indexOf('webtv')==-1) && (agt.indexOf('hotjava')==-1));
     var is_nav2 = (is_nav && (is_major == 2));
     var is_nav3 = (is_nav && (is_major == 3));
     var is_nav4 = (is_nav && (is_major == 4));
     var is_nav4up = (is_nav && (is_major >= 4));
     var is_navonly      = (is_nav && ((agt.indexOf(";nav") != -1) ||
                           (agt.indexOf("; nav") != -1)) );
     var is_nav6 = (is_nav && (is_major == 5));
     var is_nav6up = (is_nav && (is_major >= 5));
     var is_gecko = (agt.indexOf('gecko') != -1);


     var is_ie     = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera")== -1));
     var is_ie3    = (is_ie && (is_major < 4));
     var is_ie4    = (is_ie && (is_major == 4) && (agt.indexOf("msie 4")!=-1) );
     var is_ie4up  = (is_ie && (is_major >= 4));
     var is_ie5    = (is_ie && (is_major == 4) && (agt.indexOf("msie5.0")!=-1) );
     var is_ie5_5  = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.5")!=-1));
     var is_ie5up  = (is_ie && !is_ie3 && !is_ie4 && !is_ie4up);
     var is_ie5_5up =(is_ie && !is_ie3 && !is_ie4 && !is_ie5);
     var is_ie6    = (is_ie && (is_major == 4) && (agt.indexOf("msie 6.")!=-1) );
     var is_ie6up  = (is_ie && !is_ie3 && !is_ie4 && !is_ie5 && !is_ie5_5);

        if ((is_ie) && ((is_ie3)||(is_ie4)))  
           {
             alert('Your browser has been identified as an early version of Internet Explorer, which may not work correctly with some of the features of this website. If this is the case, we recommend upgrading to IE version 5 or later or using a different browser.');
            }
        else if ((is_nav) && !(is_nav4up))
            {
             alert('Your browser has been identified as an early version of Netscape Navigator, which may not work correctly with some of the features of this website. If this is the case, we recommend upgrading to Netscape version 4 or later or using a different browser.');
            }

        //alert('you are using '+agt+'.');

}