/**
 * @author martin.dilg
 */
function BandwidthChecker(imageUrl,imageFilesize,callback){
				
				imageUrl = imageUrl;
				callback = callback;
				bandwidth = 1;
				
				this.check = function(){
						
					var startTime = (new Date()).getTime(); 
					
					var img = new Image();
					
			    		img.src = imageUrl + "?msec="+startTime;
						
					var instanz = this;
					
					img.onload = function(){instanz.calcSpeed(startTime);};
					
				}
				
				this.calcSpeed = function(startTime){
				
					var stopTime = (new Date).getTime();
					var duration = (stopTime-startTime) / 1000;
					var speedKBit = Math.floor(imageFilesize /1000 * 8 / duration);
				
					bandwidth = speedKBit;
					this.callback();
				}
				
				this.callback = callback;
				
			}