// Ajax
function showUser(str) {
	if (str=="") {
		document.getElementById("txtHint").innerHTML="";
		return;
	}
	
	if (window.XMLHttpRequest) {
		xmlhttp=new XMLHttpRequest();
	} else {
		xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
	}
	
	xmlhttp.onreadystatechange=function() {
		if (xmlhttp.readyState==4 && xmlhttp.status==200) {
			document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
		}
	}
	
	xmlhttp.open("GET","index_ajax.php?q="+str,true);
	xmlhttp.send();
}