function isMSIE() {
 	if ((navigator.appName.indexOf("Explorer") != -1) && (parseInt(navigator.appVersion) >= 4)) { 
 		return true; }
 	else {return false;}
 }
 function isNS() {
 	if ((navigator.appName.indexOf("Netscape") != -1) && (parseInt(navigator.appVersion) >= 4)) {
 		return true; }
 	else {return false;}
 }
 function isPC() {
 	if (navigator.userAgent.indexOf("Win") != -1) {
 		return true; }
 	else {return false;}
 }
 function isMac() {
 	if (navigator.appVersion.indexOf("PPC") != -1) {
 		return true; }
 	else {return false;}
 }


 function do_s_write(torf) {
 theStr="";
 	if (isNS()) {
 		if (isMac()) {
 			theStr="../css/netscape_mac.css";
 		}
 		else if (isPC()) {
 			theStr="../css/netscape_pc.css";
 		}
 	}
 	if (isMSIE()) {
 		if (isMac()) {
 			theStr="../css/ie_mac.css";
 			if (navigator.userAgent.indexOf("MSIE 5") != -1) {
 				theStr="../css/ie5_mac.css";
 			}
 		}
 		else if (isPC()) {
 			theStr="../css/ie_win.css";
 		}
 	}

 if (torf==true) {
 		if (isNS()!=true && isMSIE()!=true && parseInt(navigator.appVersion)>=4) {
 			theStr="(Empty Reference!)";
 		}
 	}
 

 	if ((theStr!="") && (theStr!="(Empty Reference!)")) {
 		document.write("<LINK HREF=\""+theStr+"\" REL=\"styleSheet\" TYPE=\"text/css\">");
 	}
 } // end function