Simple jquery plugin to insert spans in text and a defined character limit

spancount.js

/**
 * Plugin function to insert spans into text:
 * usage 
 * $(document).ready(function() {
 * $('p.charcount').charSpanCount(); });
 *  or $(document).ready(function() {
 * $('p.charcount').charSpanCount({'charcount' : 15});
 *  });
 */
(function($) {
	$.fn.charSpanCount = function(options) {

		var settings = $.extend({
			// how many character before inserting span
			'charcount' : 10
		}, options);

		var insert_span = function(data) {
			var p_text = $(data).text();
			var p_length = p_text.length;
			var c = 0;
			var charc, newstr = '';
			while (c <= p_length) {
				charc = p_text.charAt(c);
				newstr = newstr + charc;
				if (c % settings.charcount == 0 && c > 1) {
					newstr = newstr + '<span>' + c + '</span>';
					$(data).html(newstr);
				}
				c++;
			}
		};
		return this.each(function() {
			insert_span($(this));
		});
	};
})(jQuery);