Asp. NET in the background with C #, to the foreground insert HTML code

For example, I have a tempstring that contains some HTML code, such as a panel and some of the controls contained therein.
I want to insert this panel (id= "Temppanel") in the background after an event is triggered in the foreground to a location in the foreground (such as the end of a div (id= "tempdiv").

public string outhtml () {
        string html= "<div> your HTML code </div>";
        return html;
}
 
The foreground page is to be inserted at
the <div><%=outhtml ()%></div>
This is one of the ways.

 
 
 
Namespace WebApplication1
{public
    partial class WebForm5:System.Web.UI.Page
    {
        protected void Page_ Load (object sender, EventArgs e)
        {

        } public
        string outhtml ()
        {
            string html = aspxhtmleditor1.html; return
            html;
        }
        public string inserthtml = string. Empty;
        protected void Aspxbutton1_click (object sender, EventArgs e)
        {
            inserthtml = aspxhtmleditor1.html;
           Outhtml ();}}