History	={
	a : [],
	n : -1 , // CurrentIndex
	add: function( nId ){
		if( History.n == History.a.length - 1 ){
			History.a.push( nId )
			} else {
				History.a = History.a.slice( 0 , History.n + 1 )
				History.a.push( nId )
				}
		History.n++
		History.setLabels()
		},
	next :function(){
		if( History.n < History.a.length - 1 ){
			History.n++
			Page.load( History.a[History.n] , 'history' )
			}
		History.setLabels()
		},
	previous :function(){
		if( History.n > 0 ){
			History.n--
			Page.load( History.a[History.n] , 'history' )
			}
		History.setLabels()
		},
	setLabels :function(){
		if( previous ){
			var nPrevious = History.a[ History.n - 1 ]
			, bPrevious = Pages.getElementById( nPrevious )
			previous.className = bPrevious ? "" : "disabled"
			previous.title = bPrevious ? Page.getPath( nPrevious ) : ''
			}
		if( next ){
			var nNext = History.a[ History.n + 1]
			, bNext = Pages.getElementById( nNext )
			next.className = bNext ? "" : "disabled"
			next.title =  bNext ? Page.getPath( nNext ) : ''
			}
		},
	out :function( evt ){
		var e = getElement( evt )
		if( e.className != "disabled" ) e.className = ""
		},
	over :function( evt ){
		var e = getElement( evt )
		if( e.className != "disabled" ) e.className = "over"
		}
	}
_("previous","next")
if( previous && next ){
	addEvents(
		[ previous , 'mousemove' , History.over ],
		[ next , 'mousemove' , History.over ],
		[ previous , 'mouseout' , History.out ],
		[ next , 'mouseout' , History.out ]
		)
	if( Nav.isIE ) 
		addEvents(
			[ previous , 'click' , History.previous ],
			[ previous , 'dblclick' , History.previous ],
			[ next , 'click' , History.next ],
			[ next , 'dblclick' , History.next ]
			)
		else addEvents(
			[ previous , 'mousedown' , History.previous ],
			[ next , 'mousedown' , History.next ]
			)
	}