some of the code that runs the lightbox feature on flickr.com

yui-lightbox.js

   function k(aC, aG, aJ) {
        var aI, aD, aO, aM, aP, aF = true, aL, Y;
        if (aC) {
            aI = K(aC)
        } else {
            return
        }
        var aN = at().width;
        if (aC.get("needs_interstitial")) {
            aF = true
        } else {
            aF = false
        }
        ++aw;
        aD = "img-" + aw;
        aO = ac.create('<div id="' + aD + '"	 data-position="' + aG + '" style="width:' + aN + 'px;" class="slide-wrap"></div>');
        aP = aO.create('<div role="img" aria-label="' + U.Escape.html(aC.get("title")) + '" class="img"></div>');
        aO.appendChild(aP);
        aM = Math.round(0.5 * (at().height - aI.scaled_height));
        aM += H ? 5 : 0;
        aO.setStyle("height", at().height + "px").setStyle("top", aM + "px");
        aP.setStyle("height", aI.scaled_height + "px").setStyle("width", aI.scaled_width + "px");
        Y = "url(" + aC.get("sizes").t.url + ")";
        if (!aF) {
            aP.setStyle("background-image", Y).setStyle("background-size", "100%")
        } else {
            aP.setStyle("background-image", "url(http://l.yimg.com/g/images/fuzzy/photo-fuzzy-t.png)").setStyle("background-size", "200%");
            aP.set("innerHTML", "<h4>" + U.transjax.get("lightbox", "outside_safesearch") + "</h4>")
        }
        ac.appendChild(aO);
        if (aG > O) {
            aO.setStyle("transform", "translate3d(" + o + "px, 0px, 0px)")
        } else {
            aO.setStyle("transform", "translate3d(-" + o + "px, 0px, 0px)")
        }
        au.setParam(aG, "id", aD);
        au.setParam(aG, "top", aM);
        au.setParam(aG, "orientation", window.orientation);
        if (!aF) {
            aL = aI.url
        } else {
            aL = "http://l.yimg.com/g/images/fuzzy/photo-fuzzy-z.png"
        }
        var aK = new Image();
        var aH = aC;
        var aE = function() {
            if (q && aH.get("sizes").l && at().width <= 480) {
                var aR = aH.get("sizes").l.url;
                var aQ = new Image();
                aQ.onload = function() {
                    aP.setStyle("background-image", "url(" + aR + ")")
                };
                aQ.src = aR
            }
        };
        aK.onload = function() {
            if (this.height != aI.height && this.width != aI.width) {
                aP.setStyle("background-image", "url(" + aH.get("sizes").l.url + ")")
            } else {
                aP.setStyle("background-image", "url(" + aL + ")")
            }
            aE();
            aK = null
        };
        U.later(20, this, function() {
            if (aK) {
                aP.setStyle("background-image", "url(" + aL + "), " + Y);
                aE()
            }
        });
        aK.src = aI.url;
        if (aJ) {
            aO.setStyle("transform", "translate(0px, 0px)")
        }
    }