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] = "gfx/button1.gif"; 
imgsrc[2] = "gfx/button1a.gif"; 
imgsrc[3] = "gfx/button2.gif"; 
imgsrc[4] = "gfx/button2a.gif"; 
imgsrc[5] = "gfx/button3.gif"; 
imgsrc[6] = "gfx/button3a.gif"; 
imgsrc[7] = "gfx/button4.gif"; 
imgsrc[8] = "gfx/button4a.gif"; 
imgsrc[9] = "gfx/button5.gif"; 
imgsrc[10] = "gfx/button5a.gif"; 
imgsrc[11] = "gfx/button6.gif"; 
imgsrc[12] = "gfx/button6a.gif"; 
imgsrc[13] = "gfx/button7.gif"; 
imgsrc[14] = "gfx/button7a.gif"; 
imgsrc[15] = "gfx/button8.gif"; 
imgsrc[16] = "gfx/button8a.gif"; 
imgsrc[17] = "gfx/button9.gif"; 
imgsrc[18] = "gfx/button9a.gif";
imgsrc[19] = "gfx/button10.gif"; 
imgsrc[20] = "gfx/button10a.gif";
imgsrc[21] = "gfx/button11.gif";
imgsrc[22] = "gfx/button11a.gif";
imgsrc[23] = "gfx/button12.gif";
imgsrc[24] = "gfx/button12a.gif";
imgsrc[25] = "gfx/button13.gif";
imgsrc[26] = "gfx/button13a.gif";
imgsrc[27] = "gfx/button14.gif";
imgsrc[28] = "gfx/button14a.gif";  

if (getAppVersion()) {
img = new Array();
for (i = 0; i < imgsrc.length; i++) {
img[i] = new Image();
img[i].src = imgsrc[i];
}
}