Contenteditable Div on Enter

<div contenteditable="true" style=background:yellow;width:400;height:400>
<div></div>
</div>

Using above ssample for contenteditable div.
After typing one line and press 'Enter' key goes to next line.
But if do a ctrl+A (Select All) and delete, then onwards 'Enter' key add 2
lines.
Seems it removes the initial '<div>' element also on 'select all- delete'
and adding '<p>' on 'Enter'.

hopes issue is clear.

How to avoid this case adding 2 lines on 'Enter' .
Is any attributes like 'DivOnReturn'??

thank in advance,
praveen






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