IE6/7/8 | IE9 | Firefox | Safari | Chrome | Opera | |
Y | Y | N | Y | Y | Y | |
N | Y | Y | Y | Y | Y |
http://msdn.microsoft.com/en-us/library/ms536377%28VS.85%29.aspx
https://developer.mozilla.org/En/DOM/Node.compareDocumentPosition
http://www.w3.org/TR/DOM-Level-3-Core/core.html#Node3-compareDocumentPosition
http://ejohn.org/blog/comparing-document-position/
function contains(a, b){
return a.contains ? a != b && a.contains(b) : !!(a.compareDocumentPosition(b) & 16);
}