var $ = function(id) { return document.getElementById(id); };
var Calendar = function(cID) {
this.calendar = $(cID);
var D = new Date();
this.year = D.getFullYear();
this.month = D.getMonth() + 1;
this.date = D.getDate();
this.onEnd = function(){};
this.init();
};
Calendar.prototype = {
constructor: Calendar,
init: function() {
var _this = this;
this.drawC( new Date(this.year, this.month, 0).getDate(), new Date(this.year, this.month - 1, 1).getDay(), new Date().getDate());
$('prevM').onclick = function() { _this.prevM(); };
$('nextM').onclick = function() { _this.nextM(); };
$('prevY').onclick = function() { _this.prevY(); };
$('nextY').onclick = function() { _this.nextY(); };
},

getDate: function() {
return new Date(this.year, this.month, 0).getDate();
},

getDay: function() {
return new Date(this.year, this.month - 1, 1).getDay();
},

drawC: function(max, start, now){
var html = '', j = 0, d = new Date(), y = d.getFullYear(), m = d.getMonth() + 1;
html += '<table id="LBody" width="180"><tbody><tr >';
while(j++ < start) {
html += '<td></td>';
}
for(var i = 0 ; i < max; i++) {
if((i + 6 + j) % 7 == 0)
html += '<tr>';
html += '<td><a onclick="cpop('+(i+1)+');" class=' + ((y == this.year && m == this.month && (i + 1) == now) ? 'now' : 'normal') + ' href="javascript:void(0);">' + (i + 1) + '</a></td>';
if(!((i + j + 1) * 7) / 7) 
html += '</tr>';
}
html += '</tbody><table>';
this.calendar.innerHTML = html;
$('showDate').innerHTML = this.year + '.' + this.month;
this.onEnd();
},

prevM: function() {
this.month--;
if(this.month < 1) { this.month = 12;this.year -= 1; }
this.drawC(this.getDate(), this.getDay(), new Date().getDate());
},

nextM: function() {
this.month++;
if(this.month > 12) { this.month = 1;this.year += 1; }
this.drawC(this.getDate(), this.getDay(), new Date().getDate());
},

prevY: function() {
this.year--;
this.drawC(this.getDate(), this.getDay(), new Date().getDate());
},

nextY: function() {
this.year++;
this.drawC(this.getDate(), this.getDay(), new Date().getDate());
}
}