How to display the word count while giving text in the ckeditor only

I need to display the word count while giving the text in ck editor only but with my above code i am able to get the word count on button click.How to display the word count directly while giving text in ck editor instead of button click

<div>
       <ckeditor:ckeditorcontrol id="CKEditor1" basepath="/ckeditor/" runat="server"></ckeditor:ckeditorcontrol>
       <asp:button id="btn1" runat="server" onclick="btn1_Click" text="get word count" />
       <asp:label id="lbl1" runat="server"></asp:label>
   </div>

protected void Page_Load(object sender, EventArgs e)
       {
       }

       protected void btn1_Click(object sender, EventArgs e)
       {
           string whole_text = CKEditor1.Text;
           string trimmed_text = whole_text.Trim();

           // new line split here
           string[] lines = trimmed_text.Split(Environment.NewLine.ToCharArray());

           // don't need this here now...
           //string[] split_text = trimmed_text.Split(' ');

           int space_count = 0;
           string new_text = "";
           foreach (string line in lines)
           {
               // Modify the inner foreach to do the split on ' ' here
               // instead of split_text
               foreach (string av in line.Split(' '))
               {
                   if (av == "")
                   {
                       space_count++;
                   }
                   else
                   {
                       new_text = new_text + av + ",";
                   }
               }
           }

           new_text = new_text.TrimEnd(',');

           // use lines here instead of split_text
           lines = new_text.Split(',');
           //MessageBox.Show(lines.Length.ToString());
           lbl1.Text = lines.Length.ToString();
       }

my above code gives the word count on button click instead i need to get the word count while typing the text in ckeditor itself.How can i do this