gistfile1.js

var input = "@ch: THIS IS A BOOK @c:professional-quality display and classified ads using a web interface. You can control the quality of these ads — and accept them later in the production cycle — while still giving your customers a wide range of creative options. At the same time, the process provides an opportunity to cross-sell and upsell your customers to higher value placements by showing them additional options during the creation process. You can even add new categories of advertisements without expending additional resources.";

var r = /(@.*?:)/g;
var k = r.exec( input );