//** jQuery Scroll to Top Control script- (c) Dynamic Drive DHTML code library: http://www.dynamicdrive.com.
//** Available/ usage terms at http://www.dynamicdrive.com (March 30th, 09')
//** v1.1 (April 7th, 09'):
//** 1) Adds ability to scroll to an absolute position (from top of page) or specific element on the page instead.
//** 2) Fixes scroll animation not working in Opera. 


var scrolltotop={
       //startline: Integer. Number of pixels from top of doc scrollbar is scrolled before showing control
       //scrollto: Keyword (Integer, or "Scroll_to_Element_ID"). How far to scroll document up when control is clicked on (0=top).
       setting: {startline:100, scrollto: 0, scrollduration:1000, fadeduration:[1500, 100]},
       controlHTML: '<img src="grafa/img/up_green.png" style="width:48px; height:48px" />', //HTML for control, which is auto wrapped in DIV w/ ID="topcontrol"
       controlattrs: {offsetx:5, offsety:5}, //offset of control relative to right/ bottom of window corner
       anchorkeyword: '#top', //Enter href value of HTML anchors on the page that should also act as "Scroll Up" links

       state: {isvisible:false, shouldvisible:false},

       scrollup:function(){
              if (!this.cssfixedsupport) //if control is positioned using JavaScript
                     this.$control.css({opacity:0}) //hide control immediately after clicking it
              var dest=isNaN(this.setting.scrollto)? this.setting.scrollto : parseInt(this.setting.scrollto)
              if (typeof dest=="string" && jQuery('#'+dest).length==1) //check element set by string exists
                     dest=jQuery('#'+dest).offset().top
              else
                     dest=0
              this.$body.animate({scrollTop: dest}, this.setting.scrollduration);
       },

       keepfixed:function(){
              var $window=jQuery(window)
              var controlx=$window.scrollLeft() + $window.width() - this.$control.width() - this.controlattrs.offsetx
              var controly=$window.scrollTop() + $window.height() - this.$control.height() - this.controlattrs.offsety
              this.$control.css({left:controlx+'px', top:controly+'px'})
       },

       togglecontrol:function(){
              var scrolltop=jQuery(window).scrollTop()
              if (!this.cssfixedsupport)
                     this.keepfixed()
              this.state.shouldvisible=(scrolltop>=this.setting.startline)? true : false
              if (this.state.shouldvisible && !this.state.isvisible){
                     this.$control.stop().animate({opacity:1}, this.setting.fadeduration[0])
                     this.state.isvisible=true
              }
              else if (this.state.shouldvisible==false && this.state.isvisible){
                     this.$control.stop().animate({opacity:0}, this.setting.fadeduration[1])
                     this.state.isvisible=false
              }
       },
       
       init:function(){
              jQuery(document).ready(function($){
                     var mainobj=scrolltotop
                     var iebrws=document.all
                     mainobj.cssfixedsupport=!iebrws || iebrws && document.compatMode=="CSS1Compat" && window.XMLHttpRequest //not IE or IE7+ browsers in standards mode
                     mainobj.$body=(window.opera)? (document.compatMode=="CSS1Compat"? $('html') : $('body')) : $('html,body')
                     mainobj.$control=$('<div id="topcontrol">'+mainobj.controlHTML+'</div>')
                            .css({position:mainobj.cssfixedsupport? 'fixed' : 'absolute', bottom:mainobj.controlattrs.offsety, right:mainobj.controlattrs.offsetx, opacity:0, cursor:'pointer'})
                            .attr({title:'Scroll Back to Top'})
                            .click(function(){mainobj.scrollup(); return false})
                            .appendTo('body')
                     if (document.all && !window.XMLHttpRequest && mainobj.$control.text()!='') //loose check for IE6 and below, plus whether control contains any text
                            mainobj.$control.css({width:mainobj.$control.width()}) //IE6- seems to require an explicit width on a DIV containing text
                     mainobj.togglecontrol()
                     $('a[href="' + mainobj.anchorkeyword +'"]').click(function(){
                            mainobj.scrollup()
                            return false
                     })
                     $(window).bind('scroll resize', function(e){
                            mainobj.togglecontrol()
                     })
              })
       }
}

scrolltotop.init()