Write C# code in html Source

Default.aspx

   

        <%if (Session["Message"] != null && Session["Message"].ToString() != "")
          {%>
       
            <%=Session["Message"] %>
       

        <%}else{%> <%= Session["Message_new"]%><%}%>

   

Default.aspx.cs

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Session["Message"] = "";
            Session["Message_new"] = "Hello welcome....";
        }
    }