ECMA Script for LoadListItemsData

var clientContext = null;
var web = null;
ExecuteOrDelayUntilScriptLoaded(Initialize, "sp.js");
function Initialize()
{
clientContext = new SP.ClientContext.get_current();
web = clientContext.get_web();
var list = web.get_lists().getByTitle("Pages");
var camlQuery = new SP.CamlQuery();
var q = '5';
camlQuery.set_viewXml(q);
this.listItems = list.getItems(camlQuery);
clientContext.load(listItems, 'Include(DisplayName,Id)');
clientContext.executeQueryAsync(Function.createDelegate(this, this.onListItemsLoadSuccess),
Function.createDelegate(this, this.onQueryFailed));
}
function onListItemsLoadSuccess(sender, args) {
var listEnumerator = this.listItems.getEnumerator();
//iterate though all of the items
while (listEnumerator.moveNext()) {
var item = listEnumerator.get_current();
var title = item.get_displayName();
var id = item.get_id();
alert("List title : " + title + "; List ID : "+ id);
}
}

function onQueryFailed(sender, args) {
alert('request failed ' + args.get_message() + '\n' + args.get_stackTrace());
}