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:300, scrollto: 0, scrollduration:1000, fadeduration:[500, 100]},
   controlHTML: '<img src="http://www.csomsk.ru/1-ucoz/pm/up-prev.png" style="width:42px; height:42px" />', //HTML for control, which is auto wrapped in DIV w/ ID="topcontrol"
   controlattrs: {offsetx:50, 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=$('<div id="topcontrol">'+mainobj.controlHTML+'</div>')
            .css({position:mainobj.cssfixedsupport? 'fixed' : 'absolute', bottom:mainobj.controlattrs.offsety, right:mainobj.controlattrs.offsetx, opacity:0, cursor:'pointer'})
            .attr({title:'Вверх'})
            .click(function(){mainobj.scrollup(); return false})
            .appendTo('body')
         if (document.all && !window.XMLHttpRequest && mainobj.$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()