JavaScript: How to find out width and height of viewpoint in browser window?

Question

How to find out width and height of viewpoint in browser window? And How to find out how much document scrolled to down and to right?

Answer 1

height = document.body.clientHeight;
width = document.body.clientWidth;

regarding scroll position, I'm not sure if there is a standard way of determining that, however this should work in most browsers:

scrolled = document.body.scrollTop;

Answer 2

Try this function... and call it when needed :)

function getViewPortSize()
{
    var viewportwidth;
    var viewportheight;

    //Standards compliant browsers (mozilla/netscape/opera/IE7)
    if (typeof window.innerWidth != 'undefined')
    {
     viewportwidth = window.innerWidth,
     viewportheight = window.innerHeight
    }

    // IE6
    else if (typeof document.documentElement != 'undefined'
    && typeof document.documentElement.clientWidth !=
    'undefined' && document.documentElement.clientWidth != 0)
    {
     viewportwidth = document.documentElement.clientWidth,
     viewportheight = document.documentElement.clientHeight
    }

    //Older IE
    else
    {
     viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
     viewportheight = document.getElementsByTagName('body')[0].clientHeight
    }

    return viewportwidth + "~" + viewportheight;
}