Copy select using JS

I’m trying to duplicate a select menu using JS. I’m very close to getting it right but need some help. What I have so far:

  for(i=document.getElementById('original-menu').options.length-1;i>=0;i--)
	{
		sel.options[i] = document.getElementById('original-menu').options[i];
	}

What it is doing is actually moving the options from select menu A to select menu B and what I want is to duplicate it. Right now when I execute the function that contains the above the original dropdown menu ends up empty with no options.

Thanks! I’ll give it a try.

The following should create new options copying the value and text from the original options rather than moving the options.

  for(i=document.getElementById('original-menu').options.length-1;i>=0;i--)
{
   sel.options[i] = 
     new Option(document.getElementById('original-menu').options[i].value,
                document.getElementById('original-menu').options[i].text);
}