• The parameter's datatype of "collapse" is not string.
• The parameter's datatype of "expand" is not string,
• The return datatype of "dataItem" is not void.

Hi I'm new to kendo and can't get the dragstart function to work.

I keep getting this error when trying to use the dragstart function
"ReferenceError: treeview is not defined", If I do define "treeview"
I get the error, "TypeError: treeview.data is not a function".

this is the function i used:
treeview.data("kendoTreeView").bind("dragstart", function (e) {
    if ($(e.sourceNode).parentsUntil(".k-treeview", ".k-item").length == 0) 
    {
       e.preventDefault();
    }
});
This is how I implemented the treeView
<div id="treeView">
   @(Html.Kendo().TreeView()
     .Name( "treeview" )
     .DragAndDrop( true )
     .DataTextField( "Title" )
     .LoadOnDemand( true )
     .DataSource( datasource => datasource
       .Read( read => read
         .Action( "PageList", "Home" )
       )
     )
     .Events( events => events
       .DragStart( "dragstart" )
       )
     )
</div>
and this is my controller code:
public class HomeController : Controller
{
  public ActionResult Index()
  {
    var pageList = BusinessLogic.Page.PageInfoList.Get();
      return View( "Index", pageList );
  }
 
  public JsonResult PageList( int? id )
  {
    var pageInfoList = PageInfoList.Get();
    var pageList = from e in pageInfoList
           where
            (
             id.HasValue ? e.ParentPageId == id : e.ParentPageId == null
            )
             select new
             {
              id = e.Id,
              Title = e.Title,
              hasChildren = (pageInfoList.Any
                    ( p => p.ParentPageId == e.Id ))
             };
 
             return Json( pageList, JsonRequestBehavior.AllowGet );
  }
}

Any help would be much appreciated.