// JavaScript Document
/* Create a new XMLHttpRequest object to talk to the Web server */
var xmlHttp = false;
var nickflg; // 0: false 1:true 2:waiting 3:error
var slanguage = "jp";
function CheckByAjax(url){
	nickflg = 0;
	try {
		xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
	} catch (e) {
		try {
			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		} catch (e2) {
			try{
				xmlHttp = new XMLHttpRequest();
			} catch (e3) {
				xmlHttp = false;
			}
		}
	}
	xmlHttp.onreadystatechange = ProcessRequest;
	xmlHttp.open("post",url, true);
	xmlHttp.send(null);
}

<!--function ProcessRequest(){
/*	try{
		var text = document.getElementById("nickname_text");
		if (xmlHttp.readyState == 4) {
			if (xmlHttp.status == 200) {
				if ("false" == xmlHttp.responseText){
					nickflg = 0;
					var user = document.getElementById("user");
					inRegOne();
					if ("jp" == slanguage){
						alert("そのニックネームは既に使われています。");
					}else{
						alert("Sorry, that nickname has already been taken.");	
					}
					user.nickname.focus();
				}else{
					nickflg = 1;
				}
			} else {
				nickflg = 3;
			}
			// alert (xmlHttp.responseText);
			text.innerHTML = "";
		}else{
			if ("jp" == slanguage){
				text.innerHTML = "少々お待ちください。ニックネームを検査しています。";
			}else{
				text.innerHTML = "Please wait ...";
			}
			nickflg = 2;
		}
	}catch(e){
		alert("ProcessRequest：" + e);
	}
}
*/-->