простейший вариант с JS:
html:
<SCRIPT language=Javascript src="mirror.js"></SCRIPT>
<img src="http://mirror1/picture_10kb.jpg" onload="imgloaded(1)" border=0>
<img src="http://mirror2/picture_10kb.jpg" onload="imgloaded(2)" border=0>
mirror.js:
PHP код:
window.onerror = "return true";
var endTime1=0;
var endTime2=0;
var diffTime;
function imgloaded(n) {
if(n == 1) endTime1=new Date();
else endTime2=new Date();
if(endTime1 > 0 && endTime2 > 0) {
diffTime = Math.ceil((endTime1.getTime() - endTime2.getTime())/1000);
if(diffTime > 0) self.location.replace('http://mirror2');
else self.location.replace('http://mirror1');
}
}