Add onkeydown event in fckeditor

I need to capture the key value to check if any of the function key (F1, F2, F3 etc..) is pressed or not. I used FCKeditor for user input. So I need to add OnKeyPress event on the textarea to call the function which will check the key value. I have searched a lot on net how to apply the OnKeyPress event, but not successful. My code is below.
PLZ PLZ help me...

<?php
include('fckeditor/fckeditor.php');
?>


function FCKeditor_OnComplete(editorInstance) {
editorInstance.Events.AttachEvent('OnKeyPress ', FCKeditor_OnKeyPress ) ;
}

function FCKeditor_OnKeyPress()
{
alert('Here');
}