Ajax - In case multiple xml file received same time:Please if is easy answer yes/no:

In case multiple xml file received same timelease if is easy answer yes/no:
I must make 3 js functions[fillNewsInfo()] that call SEPARATELLY httpRequest1.responseXML, the other httpRequest2.responseXML, and the other httpRequest3.responseXML, ...? yes/no

all these functions must be called with
httpRequest1.onreadystatechange=fillNewsInfo1;
httpRequest2.onreadystatechange=fillNewsInfo2;
httpRequest3.onreadystatechange=fillNewsInfo3;
in the updateNewsInfo() function ? yes/no

I can do this [include multiple functions] asychronyously only ? yes/no

May do a function to get httpRequest objects with a parameter like:
function getRequestObject(httpRequest) {
httpRequest = new XMLHttpRequest();
}
? yes/no what ever the param is equal the object ? yes/no

A textbox <input type"text" name="first" /> when submitted without touch it or get focus to it[hence is empty] will have $_POST['first']=null or "" or undefined ?

clearInterval(timer); in js will cause error if timer action stopped from before ? timer no exist...