ASP.NET

TextBox txtbox;
           for (int i = 1; i < 10; i++)
           {
               txtbox = new TextBox();
               txtbox.ID = "mytextbox" + i;
               txtbox.AutoPostBack = false;
               Panel1.Controls.Add(txtbox);
           }

<div id="Panel1"><br />
	<br />
        <input name="mytextbox1" type="text" id="mytextbox1" /><input name="mytextbox2" type="text" id="mytextbox2" /><input name="mytextbox3" type="text" id="mytextbox3" /><input name="mytextbox4" type="text" id="mytextbox4" /><input name="mytextbox5" type="text" id="mytextbox5" /><input name="mytextbox6" type="text" id="mytextbox6" /><input name="mytextbox7" type="text" id="mytextbox7" /><input name="mytextbox8" type="text" id="mytextbox8" /><input name="mytextbox9" type="text" id="mytextbox9" /><br />
</div>

protected void Button2_Click(object sender, EventArgs e)
    {

        IterateThroughChildren(this);
    }

    void IterateThroughChildren(Control parent)
    {
        foreach (Control c in parent.Controls)
        {
            if (c.GetType().ToString().Equals("System.Web.UI.WebControls.TextBox")
                  && c.ID == null)
            {
                TextBox txtbox = (TextBox)c;
            }

            if (c.Controls.Count > 0)
            {
                IterateThroughChildren(c);
            }
        }
    }