ajaxnetexample.js

Introduce AJAX, can learn more thing.

var itemList, itemQuantityDisplay, progressDisplay;

function onCallbackComplete(result){
    progressDisplay.style.display = "none";

    itemQuantityDisplay.className = "";
    itemQuantityDisplay.style.display = "";
    itemQuantityDisplay.innerHTML = result.value + " in stock";
}

function onCallbackError(){
    progressDisplay.style.display = "none";

    itemQuantityDisplay.className = "Error";
    itemQuantityDisplay.style.display = "";
    itemQuantityDisplay.innerHTML = "Error retrieving quantity";
}

function itemList_OnChange()
{
    document.getElementById("ProgressDisplay").style.display = "";
    document.getElementById("ItemQuantityDisplay").style.display = "none";
    
    Intro.AjaxNetExample.GetItemQuantity(itemList.value, onCallbackComplete, onCallbackError);
}

window.onload = function() {
    itemList = document.getElementById("ItemList");
    itemQuantityDisplay = document.getElementById("ItemQuantityDisplay");
    progressDisplay = document.getElementById("ProgressDisplay");

    if (itemList.attachEvent) {
        itemList.attachEvent("onchange", itemList_OnChange);
    }
    else {
        itemList.addEventListener("change", itemList_OnChange, false);
    }
}