missing reference

Question

i currently doing a web based system that has a time watch to keep track the time duration of employees working hours. I've searched for codes and found this......

 protected void Timer1_IntervalReached(object sender, CodeControls.TimerEventArgs e)
{
....
}
 protected void Timer1_IntervalReached(object sender, CodeControls.TimerEventArgs e)
{
....
}

this is just part of my .aspx.cs...
I found an error on  protected void Timer1_IntervalReached(object sender, CodeControls.TimerEventArgs e) and  protected void Timer1_IntervalReached(object sender, CodeControls.TimerEventArgs e).. It says that: "The type or namespace name 'CodeControls' could not be found(are you missing a using directive or an assembly reference?)

what does this mean??? :(

I have this in my page:
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;


what reference does this error means????

please please please help me.. I'm just a 1st year college and not good with this :(