var parameters = '';

var EventUtil = {
	addHandler : function(element, type, handler){
		if(element.addEventListener){ element.addEventListener(type,handler,false); }
		else if(element.attachEvent){ element.attachEvent('on'+type,handler); }
		else{ element['on'+type] = hanlder; }
	}
}

function validParameters(value){
  if((value == undefined) || (value == '')) return value;
  else return '&'+value;
}

function joinParameters(){
  if((parameters == undefined) || (parameters == '')) return '';
  else return '&'+parameters;
}

function customStats(custom_params){
	var path = 'http://statistics.medpass.pl?p[url]='+document.URL;
  if((custom_params == undefined) || (custom_params == '')) img.src = path;
  else img.src = path += '&'+custom_params
}

function sendStatsOnLoad(){
	img.src = 'http://statistics.medpass.pl?a=3&p[url]='+document.URL+joinParameters();
	if(navigator.userAgent.indexOf("Opera")>-1){
		img.src = 'http://statistics.medpass.pl?a=4&p[browser]=opera&p[url]='+document.URL+joinParameters();
	}
}

function sendStatsOnClose(){
	EventUtil.addHandler(window,'unload',function(){
		img.src = 'http://statistics.medpass.pl?a=4&p[url]='+document.URL+joinParameters();
	});
}

function buildHiddenImg(){
	img = document.createElement('img');
	img.id = 'hiddenImg';
	img.style.display = 'none';
	document.body.appendChild(img);
}

function prepareStatistics(){
	buildHiddenImg();
	sendStatsOnClose();
	sendStatsOnLoad();
}