Inner width - the inner dimensions of the window or frame.
var x,y;
if (self.innerHeight) // all except Explorer
{
x = self.innerWidth;
y = self.innerHeight;
}
else if (document.documentElement && document.documentElement.clientHeight)
// Explorer 6 Strict Mode
{
x = document.documentElement.clientWidth;
y = document.documentElement.clientHeight;
}
else if (document.body) // other Explorers
{
x = document.body.clientWidth;
y = document.body.clientHeight;
}
Scrolling offset - how much the page has scrolled.
var x,y;
if (self.pageYOffset) // all except Explorer
{
x = self.pageXOffset;
y = self.pageYOffset;
}
else if (document.documentElement && document.documentElement.scrollTop)
// Explorer 6 Strict
{
x = document.documentElement.scrollLeft;
y = document.documentElement.scrollTop;
}
else if (document.body) // all other Explorers
{
x = document.body.scrollLeft;
y = document.body.scrollTop;
}
Page height - the height of the total page (usually the body element).
This is a tricky one, some browsers require scrollHeight, others offsetHeight,
but all browsers support both properties. Therefore I see which property has
the larger value. This means the page height the script below gives is never sm
aller than the window height.
var x,y;
var test1 = document.body.scrollHeight;
var test2 = document.body.offsetHeight
if (test1 > test2) // all but Explorer Mac
{
x = document.body.scrollWidth;
y = document.body.scrollHeight;
}
else // Explorer Mac;
//would also work in Explorer 6 Strict, Mozilla and Safari
{
x = document.body.offsetWidth;
y = document.body.offsetHeight;
}