/**
 * Sort options (ascending or descending) in a select box (or series of select boxes)
 *
 * @name     sortOptions
 * @author   Sam Collett (http://www.texotela.co.uk)
 * @type     jQuery
 * @param    Boolean ascending   (optional) Sort ascending (true/undefined), or descending (false)
 * @example  // ascending
 * $("#myselect").sortOptions(); // or $("#myselect").sortOptions(true);
 * @example  // descending
 * $("#myselect").sortOptions(false);
 *
 */
$.fn.sortOptions = function(ascending)
{
	var a = typeof(ascending) == "undefined" ? true : !!ascending;
	this.each(
		function()
		{
			if(this.nodeName.toLowerCase() != "select") return;
			// get options
			var o = this.options;
			// get number of options
			var oL = o.length;
			// create an array for sorting
			var sA = [];
			// loop through options, adding to sort array
			for(var i = 0; i<oL; i++)
			{
				sA[i] = {
					v: o[i].value,
					t: o[i].text
				}
			}
			// sort items in array
			sA.sort(
				function(o1, o2)
				{
					// option text is made lowercase for case insensitive sorting
					o1t = o1.t.toLowerCase(), o2t = o2.t.toLowerCase();
					// if options are the same, no sorting is needed
					if(o1t == o2t) return 0;
					if(a)
					{
						return o1t < o2t ? -1 : 1;
					}
					else
					{
						return o1t > o2t ? -1 : 1;
					}
				}
			);
			// change the options to match the sort array
			for(var i = 0; i<oL; i++)
			{
				o[i].text = sA[i].t;
				o[i].value = sA[i].v;
			}
		}
	);
	return this;
};