C#

public class CusParamTextBox : BaseParam
{
    public TextBox ParamTxtBox;

    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);

        CreateCustomChildControls();
    }

    private void CreateCustomChildControls()
    {
        ParamTxtBox = new TextBox();
        ParamTxtBox.AutoPostBack = true;
        ParamTxtBox.TextChanged += new EventHandler(ParamTxtBox_TextChanged);

        base.Controls.Add(ParamTxtBox);
    }

    public void ParamTxtBox_TextChanged(object sender, EventArgs e)
    {
        TextBox cuscontrol = (TextBox)sender;
        ParamTxtBox.Text = "fired!";
        //this works.. so maybe it could be used to fire the local update event that then
        //could be exposed outside of the class.
    }

 //need to add some sort of event code for update event to expose outside of local class...
 //example ExposedUpdate()
}

//example of adding the event..

// protected override void OnInit(EventArgs e)
CusParamTextBox tmpctrlx = new CusParamTextBox();
tmpctrlx.ExposedUpdate() += new EventHandler(this.Update);

    protected void UpdateText(object sender, EventArgs e)
    {
        CusParamTextBox cuscontrol = (CusParamTextBox)sender;
        DosomethingOnPage(cuscontrol.name,cusontrol.value);
        upMain.Update();
    }