XMLのロード：解読していただきたいです

このコードがなにを示しているのかお教え頂きたいです。
もしよろしければ、どこを変更すれば汎用的になるかお教え頂きたいです。
（非常に抽象的な質問で申し訳ございません????）

javascript
1
2	//Load XML
3	function load_markers(selected){
4		$.ajax({
5			url: 'hinanLocation.xml?date=' + Date.now(),
6			type: 'get',//IEではtextを使用か
7			dataType: 'xml',
8			timeout: 1000,
9			error: function(){
10			},
11			success: function(xml,status){
12				if(status!='success'){
13					return;
14				};
15
16				$(xml).find('HinanLoc').each(function(){
17					var $id = $(this).find('ID').text();
18					var $name = $(this).find('Name').text();
19					var $opendate = $(this).find('OpenDate').text();
20					var $lat = $(this).find('lat').text();
21					var $lng = $(this).find('lng').text();
22					var $address = $(this).find('Address').text();
23					var $tel = $(this).find('Tel').text();
24					var $capacity = $(this).find('Capacity').text();
25					var $capacity_text = '避難者数：' + $capacity + '人';
26					var $status = $(this).find('Status').text();
27
28					if($status == '開設'){
29						var $status_class = 'open';
30						var $status_icon = 'icon_open';
31					} else if($status == '閉鎖' || $status == '準備中'){
32						var $status_class = 'closed';
33						var $status_icon = 'icon_closed';
34					} else {
35						var $status_class = 'open';
36						var $status_icon = 'icon_open';
37					}
38
39					if(!$address) {
40						$address_class = ' hide';
41					} else {
42						$address_class = '';
43					}
44
45					if(!$tel) {
46						$tel_class = ' hide';
47					} else {
48						$tel_class = '';
49					}
50
51					if(!$capacity) {
52						$capacity_class = ' hide';
53					} else {
54						$capacity_class = '';
55					}
56
57					var $icon = new Y.Icon('./images/marker_shelter_'+$status_class+'.png', {iconSize: new Y.Size(36,36)});
58					var $selected_option = selected;
59
60					//Proj4js.defs["EPSG:3857"] = "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +towgs84=0,0,0,0,0,0,0 +nadgrids=@null +wktext +no_defs";
61					Proj4js.defs["EPSG:2451"] = "+proj=tmerc +lat_0=36 +lon_0=139.8333333333333 +k=0.9999 +x_0=0 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs";
62
63				    // 変換元の測地系オブジェクト
64				    //var source = new Proj4js.Proj('EPSG:3857');
65				    var source = new Proj4js.Proj('EPSG:2451');
66					// 変換先の測地系オブジェクト
67					var dest = new Proj4js.Proj('EPSG:4326');
68					// 変換したい座標
69					var p = new Proj4js.Point($lat,$lng);
70					// 測地系変換関数
71					Proj4js.transform(source, dest, p); 
72					//alert(p.y + ":" + p.x);
73					
74					
75					var $marker_name = 'marker_'+$id;
76					var $marker_name = new Y.Marker(new Y.LatLng(p.y, p.x), {icon: $icon}, {title: $name});
77					var $marker_text = '<h3><span class="status ' + $status_class + '">【' + $status + '】</span>' + $name + '</h3><p class="' + $address_class + '">' + $address + '</p>' + '<a style="text-align:right;" onclick="javascript:ClickHinanjyo(' + $id + ');">詳細</a>';
78					$marker_name.bindInfoWindow($marker_text);
79
80					if($selected_option == 'all')
81					{
82						ymap.addFeature($marker_name);
83					} 
84					else if($selected_option == 'open')
85					{
86						if($status_class == 'open')
87						{
88							ymap.addFeature($marker_name);
89						}
90					} 
91					else if($selected_option == 'closed')
92					{
93						if($status_class == 'closed')
94						{
95							ymap.addFeature($marker_name);
96						}
97					}
98				});
99			}
100		});
101	}