Force IE contentEditable element to create line breaks on Enter key, without breaking Undo

Question

On Internet Explorer, a contentEditable DIV creates a new paragraph (

) each time you press Enter whereas Firefox creates a
<

Answer 1

It may be impossible to get this right. However, it is possible to make the

tags look like single line breaks, by removing the built-in margin around paragraph tags, using CSS:

p { margin: 0; }

There is a drawback to this approach: if the user needs to copy/paste text in the contentEditable element, the text may appear to be single-spaced inside the element but double-spaced outside the element.

Worse, in at least some cases, IE will automatically detect double-line breaks during paste, replacing them with

tags; this will mess up the formatting of the pasted text.