This may help you......
first you need one Panel or use div runat=server, we assume its id is dynemicContent
private void btnAdd_Click(object sender, EventArgs e)
{
TextBox t = new TextBox();
t.Name = "yourName";
Button b = new Button();
b.Name = "yourName";
b.Text = "Add";
b.Click += new EventHandler(btnAdd_Click);
this.dynemicContent.Controls.Add(t);
this.dynemicContent.Controls.Add(b);
}