var Dialog = {};
Dialog.Box = Class.create();
Object.extend(Dialog.Box.prototype, {
    initialize: function(id) {
      this.createOverlay();
  
      this.dialog_box = $(id);
      this.dialog_box.show = this.show.bind(this);
      this.dialog_box.persistent_show = this.persistent_show.bind(this);
      this.dialog_box.hide = this.hide.bind(this);
  
      this.parent_element = this.dialog_box.parentNode;
  
      this.dialog_box.style.position = "absolute";
  
      var e_dims = Element.getDimensions(this.dialog_box);
      var b_dims = Element.getDimensions(this.overlay);
  
      this.dialog_box.style.left = ((b_dims.width/2) - (e_dims.width/2)) + 'px';
      this.dialog_box.style.top = this.getScrollTop() + ((this.winHeight() - (e_dims.width/2))/2) + 'px';
      this.dialog_box.style.zIndex = this.overlay.style.zIndex + 1;
    },
  
    createOverlay: function() {
      if($('dialog_overlay')) {
        this.overlay = $('dialog_overlay');
      } else {
        this.overlay = document.createElement('div');
        this.overlay.id = 'dialog_overlay';
        Object.extend(this.overlay.style, {
        	position: 'absolute',
        	top: 0,
        	left: 0,
        	zIndex: 90,
        	width: '100%',
        	backgroundColor: '#000',
        	display: 'none'
        });
        document.body.insertBefore(this.overlay, document.body.childNodes[0]);
      }
    },
  
    moveDialogBox: function(where) {
      Element.remove(this.dialog_box);
      if(where == 'back')
        this.dialog_box = this.parent_element.appendChild(this.dialog_box);
      else
        this.dialog_box = this.overlay.parentNode.insertBefore(this.dialog_box, this.overlay);
    },
  
    show: function() {
    	
      this.overlay.style.height = this.bodyHeight()+'px';
      this.moveDialogBox('out');
      
      this.overlay.onclick = this.hide.bind(this);
      	
      this.selectBoxes('hide');
      new Effect.Appear(this.overlay, {duration: 0.1, from: 0.0, to: 0.3});
      this.dialog_box.style.display = '';
  
    	this.dialog_box.style.left = '0px';
   
      var e_dims = Element.getDimensions(this.dialog_box);
    	
    	this.dialog_box.style.left = ((this.winWidth()/2) - (e_dims.width)/2) + 'px';
    	
      this.dialog_box.style.top = this.getScrollTop() + ((this.winHeight() - (e_dims.width/2))/2) + 'px';
    	
    },
    
    getScrollTop: function() {
    	return (window.pageYOffset)?window.pageYOffset:(document.documentElement && document.documentElement.scrollTop)?document.documentElement.scrollTop:document.body.scrollTop;
    },
    
    persistent_show: function() {
      this.overlay.style.height = this.bodyHeight()+'px';
      this.moveDialogBox('out');
   
      this.selectBoxes('hide');
      new Effect.Appear(this.overlay, {duration: 0.1, from: 0.0, to: 0.3});
      
      this.dialog_box.style.display = '';
    	this.dialog_box.style.left = '0px';
      var e_dims = Element.getDimensions(this.dialog_box);
    	this.dialog_box.style.left = ((this.winWidth()/2) - (e_dims.width)/2) + 'px';
    	
    },
  
    hide: function() {
      this.selectBoxes('show');
      //new Effect.Fade(this.overlay, {duration: 0.1});
      this.overlay.style.display = 'none';
      this.dialog_box.style.display = 'none';
      this.moveDialogBox('back');
      $A(this.dialog_box.getElementsByTagName('input')).each(function(e){if(e.type!='submit')e.value=''});
    },
  
    selectBoxes: function(what) {
      $A(document.getElementsByTagName('select')).each(function(select) {
        Element[what](select);
      });
  
      if(what == 'hide')
        $A(this.dialog_box.getElementsByTagName('select')).each(function(select){Element.show(select)})
    },
    
	bodyWidth: function() { return document.body.offsetWidth || window.innerWidth || document.documentElement.clientWidth || 0; },
	bodyHeight: function() { return document.body.offsetHeight || window.innerHeight || document.documentElement.clientHeight || 0; },
  
    winWidth: function() {
		 var viewportwidth;
		 
		 // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
		 
		 if (typeof window.innerWidth != 'undefined')
		 {
		      viewportwidth = window.innerWidth;
		 }
		 
		// IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)
		
		 else if (typeof document.documentElement != 'undefined' && typeof document.documentElement.clientWidth != 'undefined' && document.documentElement.clientWidth != 0)
		 {
		       viewportwidth = document.documentElement.clientWidth;
		 }
		 
		 // older versions of IE
		 
		 else
		 {
		       viewportwidth = document.getElementsByTagName('body')[0].clientWidth
		 }
		 return viewportwidth;
    
     },
    winHeight: function() { 
		 var viewportheight;
		 
		 // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
		 
		 if (typeof window.innerHeight != 'undefined')
		 {
		      viewportheight = window.innerHeight
		 }
		 
		// IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)
		
		 else if (typeof document.documentElement != 'undefined' && typeof document.documentElement.clientHeight != 'undefined' && document.documentElement.clientHeight != 0)
		 {
		       viewportheight = document.documentElement.clientHeight;
		 }
		 
		 // older versions of IE
		 
		 else
		 {
		       viewportheight = document.getElementsByTagName('body')[0].clientHeight;
		 }
		 return viewportheight;
	
    }
  
  }); 

  
function showDialogBox(id){
	new Dialog.Box(id);
	$(id).show();
}

function closeDialogBox(id){
	$(id).hide();
}