/* =======================================================
     * ypSimpleScroll
     * 3/11/2001
     * 
    // dhtml scrolling panel featuring scrolling in any
    // direction, smooth frame-dropping animation, and a
    // few other goodies.
    //
    // 3/25/2001
    // added scrolling in any direction and initTop, initLeft
    // constructor parameters - with only 1k...
    //
    // 3/30/2001
    // fixed bug that occured when if you called scrollTo( )
    // and the new position was the same as the current
    // position. that was stupid.
    //
    // 4/02/2001
    // small bug fix - on some browsers, on slow connections
    // the script would not run at all. to be sure the doc
    // is done loading before .load() is called, the author
    // must now call the .load() method in the onload handler
    // for the page.
    //
    // 8/22/2001
    // if you tried to scroll before page was loaded it threw
    // an error. this should be fixed now.
    // 
    //
     * http://www.youngpup.net/
    //
    // =======================================================
    // ypSimpleScroll(  id, left, top, width, height, speed, 
    //          contentWidth, initScrollLeft, 
    //          initScrollTop  )
    //
    // last three parameters are optional.
     * ======================================================= */
    
    
    // basic methods.
    ypSimpleScroll.prototype.scrollNorth = function() { this.startScroll(90) }
    ypSimpleScroll.prototype.scrollSouth = function() { this.startScroll(270)  }
    ypSimpleScroll.prototype.scrollWest  = function() { this.startScroll(180) }
    ypSimpleScroll.prototype.scrollEast  = function() { this.startScroll(0)   }
    
    
    // start scrolling in an arbitrary direction, with an optional arbitrary speed.
    // if no speed is provided, the default speed from the constructor parameter is used.
    ypSimpleScroll.prototype.startScroll = function(deg, speed) {
      if (this.loaded)
      {
        if (this.aniTimer) window.clearTimeout(this.aniTimer)
        this.overrideScrollAngle(deg)
    
        this.speed    = speed ? speed : this.origSpeed
        this.lastTime = (new Date()).getTime() - this.y.minRes
        this.aniTimer = window.setTimeout(this.gRef + ".scroll()", this.y.minRes)
      }
    }
    
    // kills pending calls to .scroll(), resets speed
    ypSimpleScroll.prototype.endScroll = function() {
      if (this.loaded)
      {
        window.clearTimeout(this.aniTimer)
        this.aniTimer = 0;
        this.speed = this.origSpeed
      }
    }
    
    // override the current angle from startScroll() with a new angle
    // this method should not be used with scrollTo() because it will
    // override the angle created by the first two params to scrollTo().
    ypSimpleScroll.prototype.overrideScrollAngle = function(deg) {
      if (this.loaded)
      {
        deg = deg % 360
        if (deg % 90 == 0) {
          var cos = deg == 0  ? 1 : deg == 180 ? -1 : 0
          var sin = deg == 90 ? -1 : deg == 270 ? 1 : 0
        } else {
          var angle = deg * Math.PI / 180
          var cos   = Math.cos(angle)
          var sin   = Math.sin(angle)
          sin = -sin
        }
        this.fx = cos / (Math.abs(cos) + Math.abs(sin))
        this.fy = sin / (Math.abs(cos) + Math.abs(sin))
        this.stopH = deg == 90 || deg == 270 ? this.scrollLeft : deg < 90 || deg > 270 ? this.scrollW : 0
        this.stopV = deg == 0 || deg == 180 ? this.scrollTop : deg < 180 ? 0 : this.scrollH
      }
    }
    
    // override the speed for the current scroll.
    // should not be used with scrollTo, unless you want to 
    // override the speed computed from the aniLen param of scrollTo()
    ypSimpleScroll.prototype.overrideScrollSpeed = function(speed) {
      if (this.loaded) this.speed = speed
    }
    
    // scroll to an arbitrary position in two dimensions over in
    // an arbitrary lenth of time.
    ypSimpleScroll.prototype.scrollTo = function(stopH, stopV, aniLen) {
      if (this.loaded)
      {
        if (stopH != this.scrollLeft || stopV != this.scrollTop) {
          if (this.aniTimer) window.clearTimeout(this.aniTimer)
          this.lastTime = (new Date()).getTime()
          var dx = Math.abs(stopH - this.scrollLeft)
          var dy = Math.abs(stopV - this.scrollTop)
          var d = Math.sqrt(Math.pow(dx,2) + Math.pow(dy,2))
          this.fx = (stopH - this.scrollLeft) / (dx + dy)
          this.fy = (stopV - this.scrollTop) / (dx + dy)
          this.stopH = stopH
          this.stopV = stopV
          this.speed = d / aniLen * 1000
          window.setTimeout(this.gRef + ".scroll()", this.y.minRes)
        }
      }
    }
    
    // jump to an arbitrary position in two dimensions.
    ypSimpleScroll.prototype.jumpTo = function(nx, ny) { 
      if (this.loaded)
      {
        nx = Math.min(Math.max(nx, 0), this.scrollW)
        ny = Math.min(Math.max(ny, 0), this.scrollH)
        this.scrollLeft = nx
        this.scrollTop = ny
        if (this.y.ns4)this.content.moveTo(-nx, -ny)
        else {
          this.content.style.left = -nx + "px"
          this.content.style.top = -ny + "px"
        }
      }
    }
    
    
    
    // =========================================================================
    // =============================== private =================================
    // =========================================================================
    
    ypSimpleScroll.minRes = 10
    ypSimpleScroll.ie  = document.all ? 1 : 0
    ypSimpleScroll.ns4 = document.layers ? 1 : 0
    ypSimpleScroll.dom = document.getElementById ? 1 : 0
    ypSimpleScroll.mac = navigator.platform == "MacPPC"
    ypSimpleScroll.mo5 = document.getElementById && !document.all ? 1 : 0
    
    // recursively calls itself to animate
    ypSimpleScroll.prototype.scroll = function() {
      this.aniTimer = window.setTimeout(this.gRef + ".scroll()", this.y.minRes)
      var nt = (new Date()).getTime()
      var d = Math.round((nt - this.lastTime) / 1000 * this.speed)
      if (d > 0)
      {
        var nx = d * this.fx + this.scrollLeft
        var ny = d * this.fy + this.scrollTop
    
        var xOut = (nx >= this.scrollLeft && nx >= this.stopH) || (nx <= this.scrollLeft && nx <= this.stopH)
        var yOut = (ny >= this.scrollTop && ny >= this.stopV)  || (ny <= this.scrollTop && ny <= this.stopV)
        //window.status = nx + " " + this.fx + " " + this.scrollLeft + " " + this.stopH + " | " + ny + " " + this.fy + " " + this.scrollTop + " " + this.stopV + " : " + d
        if (nt - this.lastTime != 0 &&
          ((this.fx == 0 && this.fy == 0) ||
           (this.fy == 0 && xOut) ||
           (this.fx == 0 && yOut) ||
           (this.fx != 0 && this.fy != 0 && xOut && yOut)))
        {
          this.jumpTo(this.stopH, this.stopV)
          this.endScroll()
        }
        else {
          this.jumpTo(nx, ny)
          this.lastTime = nt
        }
      }
    }
    
    // constructor
    function ypSimpleScroll(id, left, top, width, height, speed, contentWidth, initLeft, initTop)
    {
      var y = this.y = ypSimpleScroll
      if (!initLeft)     initLeft     = 0
      if (!initTop)      initTop      = 0
      if (!contentWidth) contentWidth = width
    
      // fix for netscape4 first-page bug.
      if (document.layers && !y.ns4) history.go(0)
    
      if (y.ie || y.ns4 || y.dom) {
        this.loaded    = false
        this.id      = id
        this.origSpeed  = speed
        this.aniTimer  = false
        this.op      = ""
        this.lastTime  = 0
        this.clipH    = height
        this.clipW    = width
        this.scrollTop  = initTop
        this.scrollLeft  = initLeft
    
        // global reference to this object
        this.gRef = "ypSimpleScroll_"+id
        eval(this.gRef+"=this")
    
        var d = document
        d.write('<style type="text/css">')
        d.write('#' + this.id + 'Container { left:' + left + 'px; top:' + top + 'px; width:' + width + 'px; height:' + height + 'px; clip:rect(0 ' + width + ' ' + height + ' 0); overflow:hidden; }')
        d.write('#' + this.id + 'Container, #' + this.id + 'Content { position:absolute; }')
        d.write('#' + this.id + 'Content { left:' + (-initLeft) + 'px; top:' + (-initTop) + 'px; width:' + contentWidth + 'px; }')
        d.write('</style>')
      }
    }
    
    // once the nceesary objects are present in the DOM, this gathers some info about them.
    ypSimpleScroll.prototype.load = function() {
      var d, lyrId1, lyrId2
    
      d = document
      lyrId1 = this.id + "Container"
      lyrId2 = this.id + "Content"
    
      this.container  = this.y.dom ? d.getElementById(lyrId1) : this.y.ie ? d.all[lyrId1] : d.layers[lyrId1]
      this.content  = obj2 = this.y.ns4 ? this.container.layers[lyrId2] : this.y.ie ? d.all[lyrId2] : d.getElementById(lyrId2)
      this.docH    = Math.max(this.y.ns4 ? this.content.document.height : this.content.offsetHeight, this.clipH)
      this.docW    = Math.max(this.y.ns4 ? this.content.document.width  : this.content.offsetWidth,  this.clipW)
      this.scrollH  = this.docH - this.clipH
      this.scrollW  = this.docW - this.clipW
      this.loaded    = true
      this.scrollLeft = Math.max(Math.min(this.scrollLeft, this.scrollW),0)
      this.scrollTop  = Math.max(Math.min(this.scrollTop, this.scrollH),0)
      this.jumpTo(this.scrollLeft, this.scrollTop)
    }