var browser = navigator.userAgent.toLowerCase();
var ganzzahl = parseInt(navigator.appVersion);
var genauezahl = parseFloat(navigator.appVersion);
//ist es netscape
var netscap = ((browser.indexOf('mozilla')!=-1) && (browser.indexOf('spoofer')==-1) && (browser.indexOf('compatible') == -1) && (browser.indexOf('opera')==-1) && (browser.indexOf('webtv')==-1) && (browser.indexOf('hotjava')==-1));
var netscap4 = (netscap && (ganzzahl == 4));
var netscap4up = (netscap && (ganzzahl >= 4));
var netscaponly = (netscap && ((browser.indexOf(";nav") != -1) || (browser.indexOf("; nav") != -1)));
//ist es netscape 6
var netscap6 = (netscap && (ganzzahl == 5));
var netscap6up = (netscap && (ganzzahl >= 5));
var is_gecko = (browser.indexOf('gecko') != -1);
//ist es internet explorer 
var explorer = ((browser.indexOf("msie") != -1) && (browser.indexOf("opera") == -1));
var explorer3 = (explorer && (ganzzahl < 4));
var explorer4 = (explorer && (ganzzahl == 4) && (browser.indexOf("msie 5")==-1));
var explorer4up = (explorer && (ganzzahl >= 4));
var explorer5 = (explorer && (ganzzahl == 4) && (browser.indexOf("msie 5.0")!=-1));
var explorer5_5 = (explorer && (ganzzahl == 4) && (browser.indexOf("msie 5.5") !=-1));
var explorer5up = (explorer && !explorer3 && !explorer4);
var explorer5_5up =(explorer && !explorer3 && !explorer4 && !explorer5);
var explorer6 = (explorer && (ganzzahl == 4) && (browser.indexOf("msie 6.0") !=-1));
//ist es opera
var opera = (browser.indexOf("opera") != -1);
var opera4 = (browser.indexOf("opera 4") != -1);
var opera5 = (opera && (ganzzahl == 5));
var opera5up = (opera && (ganzzahl >=5));
var opera6down = (opera && (ganzzahl <=5));