jQuery on value changed

jQuery textChange.js

jQuery.fn.textChange = function(callback) {
	return this.each(function() {
		var lastentry = '';

		$(this).keyup(function(event) {
			var value = $(this).val();
			if (value != lastentry) {
				if (typeof callback == 'function')
					callback.call(this);
			}
			lastentry = value;
		});
	});
};