Someone

function add_incoming_extension_selector(destination_id, pattern) {
	if (pattern === undefined) pattern = '';
	var id = next_incoming_extension_selector_id;

	jQuery("#incoming_extension_selector")
		.append('<div id="incoming_extension_selector:' + id + '">')
		.append('<input name="incomingpattern:' + id + '" type="text" class="formfld" ' +
		'id="incomingpattern:' + id + '" size="20" value="' + pattern + '">')
		.append('<select name="destinationid:' + id + '" class="formfld" id="destinationid:' + id + '"></select>')
		.append('<br>')
		.append('</div>');
	
	jQuery('#destinationid:' + id).addOption(incoming_extension_selector, false);
	if (destination_id !== undefined) {
		jQuery('#destinationid:' + id).selectOptions(destination_id, true);
	}

	next_incoming_extension_selector_id++;		
}