This article is mainly on the xmlhttprequest of the cache problem for a detailed introduction, the need for friends can come to the reference, I hope to help you
In the use of XMLHttpRequest has not been encountered, the first use is good, refreshing a bit, empty the cache and then refresh again good.
This is often encountered in the use of XMLHttpRequest a problem, in some cases xmlhttprequest the results of the request will be cached in the same URL, if you request the response after different, it will produce some inexplicable problems, of course, including the article at the beginning of that hehe.
Knowing the principle is simple, that is, each request URL is different, so that it every time to go to the server side of the request, rather than using the cache. Here are two ways to use them:
The first method is to add time stamps
var url = baseurl + "×tamp=" + New Date (). GetTime ();
The second method adds a random number
var url = baseurl + "&r=" + math.random ();
There may be many other ways, as long as you can guarantee that it will go to the server every time to request the OK.