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%',
             	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.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;
    	
        }
      
      });