textrange and iframes

[Rom]

hi.
i need to select words cursor inside an iframe cause i have to do
something else after that. i read that this was obtained by using the
textrange capabilities. i was trying to select the word first but its
not working, this is the code im using so far.

function selectIt(){
var rjk;
rjk=idContent.document.body.createTextRange();
rjk.moveToPoint(window.event.x, window.event.y);
rjk.expand("word");
rjk.select();
}

idContent is the name of my iframe. Could someone tell me why it isnt
working and gimme some clues. I'd greatly appreciate it. thanks.