[javascript] JavaScript get window X/Y position for scroll

I'm hoping to find a way to get the current viewable window's position (relative to the total page width/height) so I can use it to force a scroll from one section to another. However, there seems to be a tremendous amount of options when it comes to guessing which object holds the true X/Y for your browser.

Which of these do I need to make sure IE 6+, FF 2+, and Chrome/Safari work?

window.innerWidth
window.innerHeight
window.pageXOffset
window.pageYOffset
document.documentElement.clientWidth
document.documentElement.clientHeight
document.documentElement.scrollLeft
document.documentElement.scrollTop
document.body.clientWidth
document.body.clientHeight
document.body.scrollLeft
document.body.scrollTop

And are there any others? Once I know where the window is I can set an event chain that will slowly call window.scrollBy(x,y); until it reaches my desired point.

Using pure javascript you can use Window.scrollX and Window.scrollY

window.addEventListener("scroll", function(event) {
    var top = this.scrollY,
        left =this.scrollX;
}, false);

Notes

The pageXOffset property is an alias for the scrollX property, and The pageYOffset property is an alias for the scrollY property:

window.pageXOffset == window.scrollX; // always true
window.pageYOffset == window.scrollY; // always true

Here is a quick demo

window.addEventListener("scroll", function(event) {_x000D_
  _x000D_
    var top = this.scrollY,_x000D_
        left = this.scrollX;_x000D_
  _x000D_
    var horizontalScroll = document.querySelector(".horizontalScroll"),_x000D_
        verticalScroll = document.querySelector(".verticalScroll");_x000D_
    _x000D_
    horizontalScroll.innerHTML = "Scroll X: " + left + "px";_x000D_
      verticalScroll.innerHTML = "Scroll Y: " + top + "px";_x000D_
  _x000D_
}, false);

*{box-sizing: border-box}_x000D_
:root{height: 200vh;width: 200vw}_x000D_
.wrapper{_x000D_
    position: fixed;_x000D_
    top:20px;_x000D_
    left:0px;_x000D_
    width:320px;_x000D_
    background: black;_x000D_
    color: green;_x000D_
    height: 64px;_x000D_
}_x000D_
.wrapper div{_x000D_
    display: inline;_x000D_
    width: 50%;_x000D_
    float: left;_x000D_
    text-align: center;_x000D_
    line-height: 64px_x000D_
}_x000D_
.horizontalScroll{color: orange}

<div class=wrapper>_x000D_
    <div class=horizontalScroll>Scroll (x,y) to </div>_x000D_
    <div class=verticalScroll>see me in action</div>_x000D_
</div>

Maybe more simple;

var top  = window.pageYOffset || document.documentElement.scrollTop,
    left = window.pageXOffset || document.documentElement.scrollLeft;

Credits: so.dom.js#L492

function FastScrollUp()
{
     window.scroll(0,0)
};

function FastScrollDown()
{
     $i = document.documentElement.scrollHeight ; 
     window.scroll(0,$i)
};
 var step = 20;
 var h,t;
 var y = 0;
function SmoothScrollUp()
{
     h = document.documentElement.scrollHeight;
     y += step;
     window.scrollBy(0, -step)
     if(y >= h )
       {clearTimeout(t); y = 0; return;}
     t = setTimeout(function(){SmoothScrollUp()},20);

};


function SmoothScrollDown()
{
     h = document.documentElement.scrollHeight;
     y += step;
     window.scrollBy(0, step)
     if(y >= h )
       {clearTimeout(t); y = 0; return;}
     t = setTimeout(function(){SmoothScrollDown()},20);

}