Updating List Items

$(document).ready(function() {

alert("button click");

$('#Button1').click(function(){

Button1_onclick();

});

$('#btn_Update').click(function(){

updateListItem();

});

});

function Button1_onclick() {

var title = $('#txtTitle').val();

var body = $('#txtBody').val();

createListItem(title,body);

}

function createListItem( ttl, bdy) {

alert(ttl+" "+ bdy);

var clientContext = SP.ClientContext.get_current();

var web = clientContext.get_web();

var lists = web.get_lists();

var oList = lists.getByTitle('Announcements');

var itemCreateInfo = new SP.ListItemCreationInformation();

var oListItem = oList.addItem(itemCreateInfo);

oListItem.set_item('Title', ttl);

oListItem.set_item('Body', bdy);

oListItem.update();

clientContext.load(oListItem);

clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));

}

function onQuerySucceeded() {

alert('Item created: ');

}

function onQueryFailed(sender, args) {

alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());

}

function updateListItem() {

alert("updateListItem");

var clientContext = SP.ClientContext.get_current();

var oList = clientContext.get_web().get_lists().getByTitle('Announcements');

var query = "102";

camlQuery = new SP.CamlQuery();

camlQuery.set_viewXml(query);

items = oList.getItems(camlQuery);

clientContext.load(items);

/*

this.oListItem = oList.getItemById(3);

oListItem.set_item('Title', 'My Updated Title');

oListItem.update();*/

clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));

}

function onQuerySucceeded() {

var companyEnum = items.getEnumerator();

while (companyEnum.moveNext()) {

var currentCompany = companyEnum.get_current();

var thisCompanyId = currentCompany.get_item('ID');

alert(thisCompanyId);

}

this.oListItem = oList.getItemById(4);

oListItem.set_item('Title', 'My new Title');

oListItem.set_item('Body', 'Thank You');

oListItem.update();

}

function onQueryFailed(sender, args) {

alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());

}