Hi Narayana0509,
Just to expose an example... Suppose you have the code for button in footer in your aspx page like:
<FooterTemplate >
<asp:Button ID="FooterButton" OnClick="FooterButton_Click" runat="server" Text="Footer Button" />
</FooterTemplate>
Just add an event handler in your code behind like:
protected void FooterButton_Click(object sender, EventArgs e)
{
Response.Write("<SCRIPT>alert('You have clicked footer button.');</SCRIPT>");
}
..and this will do what you need to.
Hope this helps.
Happy Coding :)