ASP.NET master page with web user control loses css and javascript

Question

I am using a master ASP.NET page to load, unload web user control dynamically based on side menu selection.

I called the java script and css files from master page. But when i load the web user control the script and css doesn't work.

It seems that the script and css applied before i load/unload the web user control as after i loaded the control and refresh the page the script and css applied to the loaded web user control again

So, is there any way to load the script and css files when load/unload web user control without refreshing the master page ?

First time i load the user control when i click the side menu

And when i refresh the page the the css and js applied as in the following image:

Can any one help ?

protected void Page_Init(object sender, EventArgs e)
        {
            if (Session["ControlName"] != null)
            {
                PControlHolder.Controls.Clear();
                LoadProductsControl(Session["ControlName"].ToString());
            }
        }
private void LoadProductsControl(string url)
        {
            PControlHolder.Controls.Clear();

            Control control = LoadControl(url);
            
            control.ID = url.Split(new char[] { '.' }, StringSplitOptions.RemoveEmptyEntries)[0];

            PControlHolder.Controls.Add(control);
        }

protected void ASPxTreeView1_NodeClick(object source,DevExpress.Web.TreeViewNodeEventArgs e)
        {
            

            if (e.Node.Nodes.Count > 0)
            {
                if (!e.Node.Expanded)
                    e.Node.Expanded = true;
                else
                    e.Node.Expanded = false;
            }

            if (e.Node.Name != "")
            {
                LoadProductsControl(e.Node.Name);
                Session["ControlName"] = e.Node.Name;
            }
        }