(function($) {
	$.fn.alphanumeric = function(p) {
		var input = $(this), az = "abcdefghijklmnopqrstuvwxyz", options = $
				.extend( {
					ichars : '!@#$%^&*()+=[]\\\';,/{}|":<>?~`.- _´¨°ºª§-¬¢£³²¹',
					nchars : '',
					allow : ''
				}, p), s = options.allow.split(''), i = 0, ch, regex;

		for (i; i < s.length; i++) {
			if (options.ichars.indexOf(s[i]) != -1) {
				s[i] = '\\' + s[i];
			}
		}

		if (options.nocaps) {
			options.nchars += az.toUpperCase();
		}
		if (options.allcaps) {
			options.nchars += az;
		}

		options.allow = s.join('|');

		regex = new RegExp(options.allow, 'gi');
		ch = (options.ichars + options.nchars).replace(regex, '');

		input.keypress(function(e) {
			var key = String.fromCharCode(!e.charCode ? e.which : e.charCode);

			if (ch.indexOf(key) != -1 && !e.ctrlKey) {
				e.preventDefault();
			}
		});

		input.blur(function() {
			var value = input.val(), j = 0;

			for (j; j < value.length; j++) {
				if (ch.indexOf(value[j]) != -1) {
					input.val('');
					return false;
				}
			}
			return false;
		});

		return input;
	};

	$.fn.numeric = function(p) {
		var az = 'abcdefghijklmnopqrstuvwxyzçáàãâéèêíìóòôõúùü', aZ = az.toUpperCase();

		return this.each(function() {
			$(this).alphanumeric($.extend( {
				nchars : az + aZ
			}, p));
		});
	};

	$.fn.alpha = function(p) {
		var nm = '1234567890';
		return this.each(function() {
			$(this).alphanumeric($.extend( {
				nchars : nm
			}, p));
		});
	};
})(jQuery);