focus checking

how can i check which element has focus? or, can i check if a specified element has focus:)

(element is a named input element in a named form)

var last;

function lastfocus(obj){
last=obj;
}

then onfocus="lastfocus(this);"

in the required elements or use the DOM to attach the event

thank you, but in some cases (i.e. on printing page) i would like to check focus, not the value of called function. (IE is one irreliable browser:/ )

what is DOM?

DOM Intro (http://brainjar.com/dhtml/intro/)