/*----------AJAX技術核心-------------*/
var xmlHttp;
function createXHR() {
	xmlHttp = false;
	if(window.XMLHttpRequest) {
		xmlHttp = new XMLHttpRequest();
		if(xmlHttp.overrideMimeType){
			xmlHttp.overrideMimeType('text/xml');
		}
	}else if(window.ActiveXObject){
		try{
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		}catch (e){
			try{
				xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
			}catch (e) {}
		}
	}
	return xmlHttp;
}