Repeating GET requests to Arduino web server - ajax

Question

So, I am currently working on a home automation project using an Arduino + Ethernet shield which is used as a web server. The webpage on the Arduino uses basic Ajax to send requests without refreshing the page or adding anything after the URL.
Here is the script:
<script type="text/javascript">
function GetArduino(url) {
var request = new XMLHttpRequest();
request.open("GET", url , false);
request.send();
}
</script>
In the HTML page I use the following to send the requests:
I then read out the HTTP requests on the Arduino and use the "L=XX" code to activate the proper lights or blinds in my house.
Now for the problem:
When using the webpage on my iPhone, every HTTP request is send 3 times in a row. This results in my lights going ON -> OFF -> ON when using Safari on my iPhone. When using Chrome on the same device, this doesn't happen.
The HTTP request looks like this on the Arduino (3 times):
new client
GET /?L=29 HTTP/1.1
Host: 192.168.1.177
Referer: http://192.168.1.177/
Accept-Encoding: gzip, deflate
Accept: */*
Accept-Language: en-us
Connection: keep-alive
User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 7_1 like Mac OS X) AppleWebKit/537.51.2 (KHTML, like Gecko) Version/7.0 Mobile/11D167 Safari/9537.53
I also noticed that Chrome does the same thing (triple HTTP request) the first time the page is loaded. After that, everything is fine.
I'm no expert in programming, so I'm probably overlooking something obvious here?

Answer 1

OK, this is embarrasing.... Turns out I was overlooking something obvious!
After searching the solution for several days (and nights!), the moment I decide to try my luck here, I find the solution.
Apparantly I had to acknowledge the request in the Arduino code:
client.println("HTTP/1.1 200 OK");
client.println();
Still strange that different browsers/devices handle this differently.