var isIE5PC = (navigator.platform.indexOf('Win32') != -1 && (navigator.appVersion.indexOf('MSIE 5') != -1 || navigator.appVersion.indexOf('MSIE 6') != -1  || navigator.appVersion.indexOf('MSIE 7') != -1)) ? 1 : 0;
var isIE4Mac = (navigator.platform.indexOf('Mac') != -1 && navigator.appVersion.indexOf('MSIE 4') != -1) ? 1 : 0;
var isIE4PC = (navigator.platform.indexOf('Win32') != -1 && navigator.appVersion.indexOf('MSIE 4') != -1) ? 1 : 0;
var isIE5Mac = (navigator.platform.indexOf('Mac') != -1 && navigator.appVersion.indexOf('MSIE 5') != -1) ? 1 : 0;
var isN6 = (document.getElementById && navigator.appName=='Netscape') ? 1 : 0;
var isNN = (!isN6 && navigator.platform.indexOf('Mac')==-1 && document.layers) ? 1 : 0;
var isNNMac = (!isN6 && navigator.platform.indexOf('Mac')!=-1 && document.layers) ? 1 : 0;