Firebug returns an error saying msg.elements is undefined. I'm trying to make a function that will enabled a delete button if any of the check boxes in a list are checked.

function selectone () {
	var msg = document.getElementsByName('pm');
	var i = 0;
	
	for(i; i < msg.elements.length; i++)
	{
		if(msg.elements[i].checked == true)
		{
			document.getElementById('multiple_action').disabled = false;
			document.getElementById('drop_button').setAttribute("class", "drop_button");
		}
		else
		{
			document.getElementById('multiple_action').disabled = true;
			document.getElementById('drop_button').setAttribute("class", "drop_button disabled");
		}
	}
}

And are there any elements in the document with the name attribute set to 'pm'?

apart from that it should be msg.length as msg does not have any properties defined in your code.