function setImg() {
    var divContent = document.getElementById("divContent");
    if (divContent) {
        var imgNodes = divContent.getElementsByTagName("img");
        for (var i = 0; i < imgNodes.length; i++) {
            var e = imgNodes[i];
            if (e.width > 640) {
                e.width = 640;
                e.style.cursor = "pointer";
                e.onclick = function() {
                    window.open(this.src, '', '');
                    return (false);
                }
            }
        }
    }
}

window.onload = setImg;