check network speed.

checkSpeed.js

function checkSpeed(){
		var start_time = Date.now();
		var fileSizeCall = $.ajax({
		  type: "HEAD",
		  url: "//tatocaster.me/20MB.zip",
		  success: function(msg){
		  	// 1sec == 1000ms .
		  	var timeSecs = Math.round((Date.now() - start_time)+3)/100;
		  	//1mbps == 1000kbps
		  	var sizeMB = fileSizeCall.getResponseHeader('Content-Length')/1000000;
		  	var result = Math.round(sizeMB/timeSecs);
		  	// alert('Connection Speed is ' + result + ' Mbps');
		  }
		});
	}