Описание тега actualheight
ActualHeight is set by the rendering system, and may be different depending on the heights of other elements and overall size constraints. As a result, it can not be changed.
window.innerHeight/Width: Provided by most browsers, but not Internet Explorer 8-, and even in Internet Explorer 9+, it is not available in quirks mode.document.body.clientHeight/Width: Provided by many browsers, including Internet Explorer.document.documentElement.clientHeight/Width:Provided by most DOM browsers, including Internet Explorer.
| | document. | document.
| window | body. | documentElement.
Browser | innerHeight | clientHeight | clientHeight
------------------| ------------|--------------|-----------------
Opera 9.5+ strict | window | document | window
Opera 9.5+ quirks | window | window | document
Opera 7-9.2 | window | window | document
Opera 6 | window | window | N/A
Mozilla strict | window | document | window
Mozilla quirks | window | window | document
Newer KHTML | window | document | window
Older KHTML | window | document | document
Chrome/Safari 4+ | window | document | window
Safari 3- | window | document | document
iCab 3 | window | document | document
iCab 2 | window | window | N/A
IE 9+ strict | window | document | window
IE 6-8 strict | N/A | document | window
IE 5+ quirks | N/A | window | 0
IE 4 | N/A | window | N/A
ICEbrowser | window | window | document
Tkhtml Hv3 | window | window | document
Netscape 4 | window | N/A | N/A