ECMA Script : To create a new list item in SharePoint 2010

 
<script language="ecmascript" type="text/ecmascript">
 
    var clientContext = null;
    var oWeb = null;
    var oListColl = null;
    var oList = null;
    var oListItem = null;
    var listItemCreationInfo = null;
   
 
    function createListItem() {
        clientContext = new SP.ClientContext.get_current();
        oWeb = clientContext.get_web();
        oListColl = oWeb.get_lists();
        oList = oListColl.getByTitle('Custom List');
        listItemCreationInfo = new SP.ListItemCreationInformation();
        oListItem = oList.addItem(listItemCreationInfo);
        oListItem.set_item('Title', 'New Item');
        oListItem.update();
        clientContext.load(oListItem);
        clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));
    }
 
    function onQuerySucceeded() {
        
        alert(oListItem.get_title() + ' item is created successfully.');
    }
 
    function onQueryFailed(sender, args) {
        alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
    }
 
 
 
</script>
<input id="btnCreateListItem" onclick="createListItem()" type="button" value="Create List Item"/>