I don't want to use ajaxmethod because it is an webservice which has different url

Ext.MessageBox.confirm('Save?', 'Save?', function(btn) {
    if (btn == "yes") {
       callAjaxEvent();
    }
});


<CustomAjaxEvents>
    <ext:AjaxEvent EventName="ABCD" Url="/WebService/R.asmx/Ru" Type="Submit" Method="POST" CleanRequest="true">
          <ExtraParams>
              <ext:Parameter Encode="true" Name="k" Value="1" />
          </ExtraParams>
    </ext:AjaxEvent>
</CustomAjaxEvents>