var imgSwapping = false;
imgSwapping = (document.images) ? true : false;
//var imgSwapping = ((navigator.appname) = indexofExplorer) ? true : false;
//if(document.images)imgSwapping = true;
//if(navigator.appname == "Netscape")imgSwapping = false;
imgSwapping = (document.images) && !((navigator.appName == "Netscape") && (navigator.appVersion.substring(0,2) == "3."));
function imgOnErrorHandler () { alert ("Unable to load : " + this.src); }
function newImageObjects (num) { var i; if (imgSwapping) { for (i = 0; i < num; i++) { eval ('im' + i + ' = new Image ();'); eval ('im' + i + '.onerror = imgOnErrorHandler;'); } } else for (i = 0; i < num; i++) eval ('im' + i + ' = new Object ();'); }
function assignImageURLS () { var numImageObjects = assignImageURLS.arguments.length; var i; newImageObjects (numImageObjects); for (i = 0; i < numImageObjects; i++) eval ('im' + i + '.src = "' + assignImageURLS.arguments[i] + '"'); } function imswap_obj (onSrc, offSrc, status) { this.status = status; this.onSrc = onSrc; this.offSrc = offSrc; this.tImages = new Object (); }
assignImageURLS ('images/main01off.gif', 'images/main01on.gif', 'images/main03off.gif', 'images/main03on.gif', 'images/pop.gif', 'images/pop01.gif', 'images/pop02.gif');

image1 = new imswap_obj (im1, im0, 'Visit The New York Public Library\'s main web site.');
image1.tImages.pop = new imswap_obj (im5, im4);
image2 = new imswap_obj (im3, im2, 'The online home of The New York Public Library\'s Mid-Mahattan Library Digital Picture Collection.');
image2.tImages.pop = new imswap_obj (im6, im4);

imStat = new Object ();
imStat.image1 = image1;
imStat.image2 = image2;

function img_act (imgName) {
if (imgSwapping) {
document[imgName].src = imStat[imgName].onSrc.src;
for (name in imStat[imgName].tImages)
document[name].src = imStat[imgName].tImages[name].onSrc.src;
}
if (imStat[imgName].status)
window.status = imStat[imgName].status;
return true;
}
function img_inact (imgName) {
if (imgSwapping) {
document[imgName].src = imStat[imgName].offSrc.src;
for (name in imStat[imgName].tImages)
document[name].src = imStat[imgName].tImages[name].offSrc.src;
}
window.status = 'The New York Public Library Digital Picture Collection.';
return true;
}