This tip is helpful to stop the client from caching content.
Open your local XML file.
This can be found in the [Magento Root]/app/etc/local.xml
Locate the follow area under the <global> node, and insert the code from line 26:
After you save and commit your changes, clear your Magento cache for the site.
Log into your Magento Dashbaord, and go to Systems > Cache Management
Next, select all the the Cache Types. Set your Action to: Refresh, and click the orange Submit button
We advise not to run this action for more than a week to maintain positive performance.