step1

var oldCreateElement = document.createElement;
document.createElement = function() {
    var element = oldCreateElement.apply(document, arguments);
    var oldSetAttribute = element.setAttribute;
    console.log(arguments, element); 
    element.setAttribute = function(name, value) {
        if (name == "onsubmit") {
            console.log(arguments.callee.caller.toString());
        }
        oldSetAttribute.apply(element, arguments);
    }
    return element;
}