/**
 * Describe Regions Action Sample
 * The DescribeRegions operation describes regions zones that are currently available to the account.  
 * @param Amazon_EC2_Interface $service instance of Amazon_EC2_Interface
 * @param mixed $request Amazon_EC2_Model_DescribeRegions or array of parameters
 */
function invokeDescribeRegions(Amazon_EC2_Interface $service, $request)
{
    try {
        $response = $service->describeRegions($request);
        echo "Service Response\n";
        echo "=============================================================================\n";
        echo "        DescribeRegionsResponse\n";
        if ($response->isSetResponseMetadata()) {
            echo "            ResponseMetadata\n";
            $responseMetadata = $response->getResponseMetadata();
            if ($responseMetadata->isSetRequestId()) {
                echo "                RequestId\n";
                echo "                    " . $responseMetadata->getRequestId() . "\n";
            }
        }
        if ($response->isSetDescribeRegionsResult()) {
            echo "            DescribeRegionsResult\n";
            $describeRegionsResult = $response->getDescribeRegionsResult();
            $regionList = $describeRegionsResult->getRegion();
            foreach ($regionList as $region) {
                echo "                Region\n";
                if ($region->isSetRegionName()) {
                    echo "                    RegionName\n";
                    echo "                        " . $region->getRegionName() . "\n";
                }
                if ($region->isSetEndpoint()) {
                    echo "                    Endpoint\n";
                    echo "                        " . $region->getEndpoint() . "\n";
                }
            }
        }
    } catch (Amazon_EC2_Exception $ex) {
        echo "Caught Exception: " . $ex->getMessage() . "\n";
        echo "Response Status Code: " . $ex->getStatusCode() . "\n";
        echo "Error Code: " . $ex->getErrorCode() . "\n";
        echo "Error Type: " . $ex->getErrorType() . "\n";
        echo "Request ID: " . $ex->getRequestId() . "\n";
        echo "XML: " . $ex->getXML() . "\n";
    }
}