var isMSIE      = (navigator.appVersion.indexOf("MSIE") != -1) ? true : false;
var isMSIE5     = isMSIE && (navigator.userAgent.indexOf('MSIE 5') != -1);
var isMSIE6     = isMSIE && (navigator.userAgent.indexOf('.NET') != -1);
var isGecko     = navigator.userAgent.indexOf('Gecko') != -1;
var isSafari    = navigator.userAgent.indexOf('Safari') != -1;
var isOpera    = (navigator.userAgent.indexOf("Opera") != -1) ? true : false;

var isWin      = (navigator.appVersion.toLowerCase().indexOf("win") != -1) ? true : false;
var isMac       = navigator.userAgent.indexOf('Mac') != -1;