Add label at run time on user button click

i have a text box and a button, evrytime when user enter something in textbox and click on button then the text of  textbox is apear on label .
along with the previous text of textbox...

<form id="form1" runat="server"><div><asp:Label ID="Label1" runat="server" Text="Placeholder control Example showing Textbox at runtime" Font-Underline="true" Font-Bold="true"></asp:Label></div><p><asp:PlaceHolder ID="plcHolder" runat="server"></asp:PlaceHolder></p><hr /><asp:TextBox runat="server" ID="txtMsg"></asp:TextBox><p><asp:Button ID="btnSubmit" runat="server" Text="Click me" OnClick="Button1_Click" /></p></form>