Button Click function from modal on code behind

i have this modal :

<div class="modal fade" id="ModalServiceCalls" tabindex="-1" role="dialog" aria-labelledby="myModalLabel"
        aria-hidden="true">
        <div class="modal-dialog modal-sm">
            <div class="modal-content">
                <div class="modal-header">
                    <button type="button" class="close" data-dismiss="modal" aria-hidden="true" dir="rtl" id="CloseBTN">
                        &times;</button>
                    <h4 class="modal-title">
                        service call</h4>
                </div>
                <div class="modal-body">
                </div>
                <br />
                <asp:Button ID="ServiceCallBTN" runat="server" Text="סגור קריאה" CssClass="btn btn-default"
                    Font-Bold="true" />
                <div class="modal-footer">
                    <button type="button" class="btn btn-default" data-dismiss="modal">
                        close</button>
                    <button type="button" class="btn btn-primary">
                        save changes</button>
                </div>
            </div>
            <!-- /.modal-content -->
        </div>
        <!-- /.modal-dialog -->
    </div>

I want to create a function in code behind that will start with this button click. This is the code behind function:

 protected void ServiceCallBTN_Click(object sender, EventArgs e)
 {
        Response.Write("checking");
 }

The problem is that this function is not even fired.