var ns4 = (document.layers)? true:false;
var ie  = (document.styleSheets&&document.all)? true:false; //IE ab Version 4
var ns6 = (document.getElementById&&!document.all)? true:false;
var mac = ((navigator.appVersion.indexOf('Mac')>0) || (navigator.appVersion.indexOf('mac')>0)) ? true : false;
var win = ((navigator.appVersion.indexOf('Win')>0) || (navigator.appVersion.indexOf('win')>0)) ? true : false;

function browserDetection(iepc,iemac,ns4pc,ns4mac,ns6pc,ns6mac){
	if((ie)  && (win)) return iepc;
	if((ie)  && (mac)) return iemac;
	if((ns4) && (win)) return ns4pc;
	if((ns4) && (mac)) return ns4mac;
	if((ns6) && (win)) return ns6pc;
	if((ns6) && (mac)) return ns6mac;
}

//alert(browserDetection("iepc","iemac","ns4pc","ns4mac","ns6pc","ns6mac"));