image polling through javascript -

i need poll image using javascript , need perform action once image found @ position. code have written task.

/*----image handling script starts here----*/ var beacon = new image();  beacon.onload = function() {     console.log('image found');      console.log(this.width,this.height);     window.clearinterval(timer); }; beacon.onerror = function(){        console.log('image not found'); } var timer = window.setinterval(function(){     console.log('sending request again');     beacon.src = "http://www.google.co.in/logos/2010/lennon10-hp.gif"; },2000); /*----image handling script ends here----*/ 

problem that, after 1 request, response gets cached , request don't sent everytime set src. if examine net tab, sends request on first src set , caches response.

i need send fresh request image every time code sets src. workarounds?

request image different query string each time. browser treat unique url , won't have in cache. can away because it's web server ignore in query string when requesting image. following should make 100 requests:

for (var i=0; i<100; i++) {     beacon.src = "http://www.google.co.in/logos/2010/lennon10-hp.gif?" + i; }