// new code
var request = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("MSXML2.XMLHTTP.3.0");

function showHairInfo(col, len) {
	var url="/ajax_hair_info.php?col=" + col + "&len=" + len;
	
	ajax(url, null, stateChangedLen);
}

function stateChangedLen(){
	if (request.readyState==1){
		document.getElementById("hair_info").innerHTML="Loading ..."
	} else if (request.readyState == 4 && request.status == 200) {
	        if (request.responseText){
	                document.getElementById("hair_info").innerHTML=request.responseText;
	        }
	}
}

function ajax(url, vars, callbackFunction){
	// for some reason using post and uncommenting the line below doesn't work
        request.open("GET", url, true);
        //request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
 
        request.onreadystatechange = callbackFunction;
        
        request.send(vars);
}