Using this code:
var pendingRequest = new Ajax.Request(myUrl, { method: \'post\', postBody: soapMsg, contentTyp
I reccomend this article: http://blog.pothoven.net/2007/12/aborting-ajax-requests-for-prototypejs.html works for me.
You can use XHR's abort.
The XHR-object is stored in pendingRequest.transport, so using
pendingRequest.transport.abort()
would cancel the request.