function ajax(stranka, kam) {
	var httpRequest;
	if(typeof window.ActiveXObject != 'undefined') {
		httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
	} else {  
		httpRequest = new XMLHttpRequest();
	}
	httpRequest.open("GET", stranka, true);
	httpRequest.onreadystatechange = function () { processRequest(httpRequest, kam) };
	httpRequest.send(null);
}

function processRequest(httpRequest, kam) {
	if (httpRequest.readyState == 4) {
		if(httpRequest.status == 200) {
			if (typeof kam == 'string') {
				document.getElementById(kam).innerHTML = httpRequest.responseText;
			}
			if (typeof kam == 'function') {
				kam(httpRequest.responseText);
			}
		} else {
			alert("Chyba při načítání stránky " + httpRequest.status +" : "+ httpRequest.statusText);
		}
	}
} 

function mojefunkce(parametr) {
	alert(parametr);
}