Js_javascript tips for getting the page, window height and width accurately

function GetPageSize () {

var xscroll, Yscroll;

if (window.innerheight && window.scrollmaxy) {
Xscroll = Document.body.scrollWidth;
Yscroll = Window.innerheight + window.scrollmaxy;
else if (Document.body.scrollHeight > Document.body.offsetHeight) {//all but Explorer Mac
Xscroll = Document.body.scrollWidth;
Yscroll = Document.body.scrollHeight;
else {//Explorer mac...would also work in Explorer 6 Strict, Mozilla and Safari
Xscroll = Document.body.offsetWidth;
Yscroll = Document.body.offsetHeight;
}

var windowwidth, WindowHeight;
if (self.innerheight) {//all except Explorer
WindowWidth = Self.innerwidth;
WindowHeight = Self.innerheight;
else if (document.documentelement && document.documentElement.clientHeight) {//Explorer 6 Strict Mode
WindowWidth = Document.documentElement.clientWidth;
WindowHeight = Document.documentElement.clientHeight;
else if (document.body) {//other explorers
WindowWidth = Document.body.clientWidth;
WindowHeight = Document.body.clientHeight;
}

For small pages and total height less then height of the viewport
if (Yscroll < WindowHeight) {
PageHeight = WindowHeight;
} else {
PageHeight = Yscroll;
}

For small pages and total width less then width of the viewport
if (Xscroll < windowwidth) {
PageWidth = WindowWidth;
} else {
PageWidth = Xscroll;
}


Arraypagesize = new Array (pagewidth,pageheight,windowwidth,windowheight)
return arraypagesize;
}
Fortunate enough to find your this dongdong, help me solve the problem, but looked carefully, as if there is a big problem, parameter value and name on the look like a bit on the number OH.
For small pages and total height less then height of the viewport
if (Yscroll < WindowHeight) {
PageHeight = Yscroll;
} else {
PageHeight = WindowHeight;
}

For small pages and total width less then width of the viewport
if (Xscroll < windowwidth) {
PageWidth = Xscroll;
} else {
PageWidth = WindowWidth;
}