function getAppVersion() {
appname= navigator.appName;
appversion = navigator.appVersion;
majorver = appversion.substring(0, 1); 
if ( (appname == "Netscape") && ( majorver >= 3 ) ) return 1;
if ( (appname == "Microsoft Internet Explorer") && (majorver >= 4) ) return 1;
return 0;
}
function swtch(num, imgname) {
if (getAppVersion()) {
document[imgname].src = img[num].src;
}
}
imgsrc = new Array();

imgsrc[1] = "img/menu/rules_1.gif"; 
imgsrc[2] = "img/menu/rules_2.gif"; 
imgsrc[3] = "img/menu/deadline_1.gif"; 
imgsrc[4] = "img/menu/deadline_2.gif";
imgsrc[5] = "img/menu/account_1.gif";
imgsrc[6] = "img/menu/account_2.gif";
imgsrc[7] = "img/menu/summary_1.gif";
imgsrc[8] = "img/menu/summary_2.gif";
imgsrc[9] = "img/menu/ordering_1.gif"; 
imgsrc[10] = "img/menu/ordering_2.gif"; 
imgsrc[11] = "img/menu/logout_1.gif"; 
imgsrc[12] = "img/menu/logout_2.gif"; 
if (getAppVersion()) {
img = new Array();
for (i = 0; i < imgsrc.length; i++) {
img[i] = new Image();
img[i].src = imgsrc[i];
}
}