Mac GUI Automation using Applescript

I would like to have an Applescript that automates some actions on iWork '09 Keynote on Mac 10.6. ? The workflow is the following: 1. ? Assuming a Keynote? presentation? is? already open. 2. ? Click "File"->"Export...". ? This will open the Export dialog box. 3. ? Click the "Image" tab on the top, and select "Slides->All", and "Format->JPEG". ? Then, Click "Next..." 4. ? Click "Export" at the "Save As" box. That's it. The Applescript will run all above steps without user intervention.