UserControl not capturing Button click event when loaded with PlaceHolder Control

protected void Page_Load(object sender, EventArgs e)
{
if (!base.IsPostBack)
{
switch (((base.Request.QueryString["Page"] != null) ? base.Request.QueryString["Page"].ToUpper() : "HOME"))
{
case "CONTACT":
phdDefault.Controls.Clear();
Control myUserControl = (Control)Page.LoadControl("Modules/WebUserControl.ascx");
phdDefault.Controls.Add(myUserControl);
break;
}
}
}

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
<asp:Label ID="Label1" runat="server"></asp:Label>

protected void Button1_Click(object sender, EventArgs e)
{
// OnBubbleClick(e);
TextBox1.Text = "";
Label1.Text = "What is this an error ?";
}