How to measure the position of an element in web page using selenium RC?

I have tried 开发者_StackOverflow社区a lot in finding out how measure the coordinate of an element in a web page in different browser.But I could not find any solution.

Is there any other tool that can measure the position of an element in various browsers???

In AutoIt you can use the following code to get screen coordinates (in my example for displaying a tool tip as an overlay on an Internet Explorer):

$oIE = _IECreate("http://...URL...")
$username = _IEFormElementGetObjByName(_IEFormGetObjByName($oIE, "loginform"), "username")
ToolTip("Login", _IEPropertyGet($username, "screenx"), _IEPropertyGet($username, "screeny"))
_IEAction($username, "focus")

Alternatively you can use _IEGetObjById($oIE, "mx77") to get an object reference. Or run through all all elemnts by tag name as shown here. Instead of getting the absolute screen position, you can get the In-Browser-Position, using browserx and browsery.