protected override void OnPreRenderComplete(EventArgs e)
{
//------------------------------------------------------------------------------------------------------
//TODO: We should be able to remove this code once we update DevExpress to a recent version.
// Problem exists in the DevExpress dropdown controls used on the
// Select Payemnt Method - Change Expiration Date Month-Year controls.
// This was a known issue at DevExpress for IE9+ versions, and was fixed in version 2010 and later
// version 2010 and later. http://www.devexpress.com/Support/Center/Question/Details/B192965
//------------------------------------------------------------------------------------------------------
base.OnPreRenderComplete(e);
Page.Header.Controls.AddAt(0, new HtmlMeta { HttpEquiv = "X-UA-Compatible", Content = "IE=8" });
}
<script type="text/javascript" >
var orig_aspxEmulateDocumentOnMouseDown = _aspxEmulateDocumentOnMouseDown;
_aspxEmulateDocumentOnMouseDown = function _aspxEmulateDocumentOnMouseDown(evt)
{
var emulatedEvt = document.createEvent("MouseEvents");
emulatedEvt.initMouseEvent("mousedown", true, true, window, 0, evt.screenX, evt.screenY,
evt.clientX, evt.clientX, evt.ctrlKey, evt.altKey, evt.shiftKey, false, 0, null);
document.dispatchEvent(emulatedEvt);
}
</script>