function getXMLHttpRequest(){
	if (window.ActiveXObject){
		try{
			return new ActiveXObject("Msxml2.XMLHTTP");
		}catch(e){
			try{
				return new ActiveXObject("Microsoft.XMLHTTP");
			}catch(e1){return null;}
		}
	}else if(window.XMLHttpRequest){
		return new XMLHttpRequest();
	}else{
		return null;
	}
}

var httpRequest=null;

function sendRequest(url, params, callback, method){
	httpRequest=getXMLHttpRequest();
	var httpMethod=method ? method : 'GET'; //method°ªÀÌ ÀÖÀ¸¸é method, ¾øÀ¸¸é ±âº» 'GET'
	if(httpMethod != 'GET' && httpMethod != 'POST'){
		httpMethod='GET';
	}
	var httpParams=(params == null || params == '') ? null : params; //params: ¿¹·Î book.asp?no=1¿¡¼­ ¹°À½Ç¥µÚ¿¡ ÀÖ´Â °ÍµéÀ» ÀǹÌ
	var httpUrl=url;
	if(httpMethod == 'GET' && httpParams != null){ //get¹æ½ÄÀº urlµÚ¿¡ ¹°À½Ç¥¸¦ »ç¿ë
		httpUrl=httpUrl + "?" + httpParams;
	}
	httpRequest.open(httpMethod, httpUrl, true);
	httpRequest.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
	httpRequest.onreadystatechange=callback;
	httpRequest.send(httpMethod == 'POST' ? httpParams : null);
}