//browser sniffer
var agt=navigator.userAgent.toLowerCase();
var is_major = parseInt(navigator.appVersion);
var is_minor = parseFloat(navigator.appVersion);

var is_nav = ((agt.indexOf('mozilla')!=-1)
    && (agt.indexOf('spoofer')==-1)
    && (agt.indexOf('compatible') == -1)
    && (agt.indexOf('opera')==-1)
    && (agt.indexOf('webtv')==-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_nav5 = (is_nav && (is_major == 5));
var is_nav5up = (is_nav && (is_major >= 5));

var is_ie = (agt.indexOf("msie") != -1);
var is_ie3 = (is_ie && (is_major < 4));
var is_ie4 = (is_ie && (is_major == 4) &&
    (agt.indexOf("msie 5.0")==-1) );
var is_ie4up = (is_ie && (is_major >= 4));
var is_ie5 = (is_ie && (is_major == 4) &&
    (agt.indexOf("msie 5.0")!=-1) );
var is_ie5up = (is_ie && !is_ie3 && !is_ie4);

var is_aol = (agt.indexOf("aol") != -1);
var is_aol3 = (is_aol && is_ie3);
var is_aol4 = (is_aol && is_ie4);

var is_opera = (agt.indexOf("opera") != -1);
var is_webtv = (agt.indexOf("webtv") != -1);


// os detection
var is_pc=(navigator.platform.substring(0,3)=='Win');
var is_mac=(navigator.platform.substring(0,3) == 'Mac')

// resolution check

var sw=screen.availWidth;
var sh=screen.availHeight;



// color depth check
var color_depth= window.screen.colorDepth;