var xmlHttp

function login() {
	showpage("?act=login&name=" + login_form.txtName.value + "&pass=" + login_form.txtPass.value);
}

function showpage(str) {
	xmlHttp=GetXmlHttpObject();
	
	if (xmlHttp==null) {
		alert ("Your browser does not support AJAX!");
		return;
	}
	
	xmlHttp.onreadystatechange=stateChanged;
	xmlHttp.open("GET","callback.php"+str,true);
	xmlHttp.send(null);
}

function stateChanged() {
	if (xmlHttp.readyState==4) {
		document.getElementById("login").innerHTML=xmlHttp.responseText;
	}
}

function GetXmlHttpObject() {
	var xmlHttp=null;
	
	try {
		// Firefox, Opera 8.0+, Safari
		xmlHttp=new XMLHttpRequest();
	} catch (e) {
		// Internet Explorer
		try {
			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	
	return xmlHttp;
}