Restricting enter keypress event in an IFrame, does not work

Question

I have an IFrame within my page and am using the designMode="on" on this iframe for a small-level rich text editing.

My concern is that I need not allow the user to enter new lines in it - meaning, I want to restrict enter keys.

I did it using the question posted here to listen to the keypress events. But in my keypress event, if I return false, nothing happens.

How do I restrict enter keys in Iframe with designmode?

Code :

      document.getElementById('editor').contentWindow.addEventListener('keypress',restrictEnterKey, true);

            function restrictEnterKey(event) {
                var key=(event.charCode)?event.charCode:((event.keyCode)?event.keyCode:((event.which)?event.which:0));
                if (key == 13) {
                    //alert('me');
                    return false;
                }
                return true;
            }

Answer 1

You need to call preventDefault on the event or set returnValue to false for IE. The following function will do the job:

function preventDefault(evt) {
    if (evt.preventDefault) {
        evt.preventDefault();
    } else if (typeof evt.returnValue !== "undefined") {
        evt.returnValue = false;
    }
}