如何在JavaScript中改进这个if else结构？

Question

如何在JavaScript中改进以下if-else结构？

if(isIE())
    if(termin != "")
        TargetElement.onclick = function() {merkzettelRemove(this, id, termin)};
    else
        TargetElement.onclick = function() {merkzettelRemove(this, id)};
    else
        if(termin != "")
            TargetElement.setAttribute("onclick","merkzettelRemove(this, " + id + ",
               '" + termin + "')");
        else
            TargetElement.setAttribute("onclick","merkzettelRemove(this, " + id + ")");

Answer 1

// get a cross-browser function for adding events
var on = (function(){
    if (window.addEventListener) {
        return function(target, type, listener){
            target.addEventListener(type, listener, false);
        };
    }
    else {
        return function(object, sEvent, fpNotify){
            object.attachEvent("on" + sEvent, fpNotify);
        };
    }
}());

// add the event listener
on(TargetElement, "click", function(){
    // if termin is empty we pass undefined, this is the same as not passing it at all
    merkzettelRemove(this, id, (termin) ? termin : undefined);
});