function xmlRequest(url){
        var http_request = false;
        if (window.XMLHttpRequest) { 
      // Mozilla, Safari,...
            http_request = new XMLHttpRequest();
            if (http_request.overrideMimeType) {
                http_request.overrideMimeType('text/xml');
                // See note below about this line
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            }catch(e){
                try {
                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) 
               {}
            }
        }
        if (!http_request) {
            alert('Not create xmlhttp request.');
            return false;
        }
        http_request.onreadystatechange = function() { 
      loadData(http_request); 
  };
        http_request.open('GET', url, true);
        http_request.send(null);
}//end function

function loadData(http_request){
     /* handle changed http request state
     1 : loading
     2 : loaded
     3 : Interactive
     4 : Done 
  */
     if(http_request.readyState == 1){
		catalog_show.innerHTML="<center><img src='images/loading.gif'></center>";
	  }
	if (http_request.readyState == 4){
	  // 200 OK
		if (http_request.status == 200){
			catalog_show.innerHTML=http_request.responseText;
		} else {
			catalog_show.innerHTML="Sorry someThing wrong!";
		}
	}
}//end function