Rails spinoffs - Oct 2005 - aborting xmlhttp requests?

Hi,

I just wanted to find out if it is good thing to cancel any existing
xmlhttprequests using the abort method (when there are existing connections)
when the next request is fired?
Does the scriptaculous / prototype library take care of this or does the browser
automatically take care of this?

Is something like the following necessary?

    // check for existing requests
   
if(xmlobj!=null&&xmlobj.readyState!=0&&xmlobj.readyState!=4){
        xmlobj.abort();
    }

Thanks in advance,
Mandy.