Applying review comments.

lib/services/serviceManagement/servicemanagementservice.js

@@ -728,6 +728,10 @@ ServiceManagementService.prototype.regenerateStorageAccountKeys = function(servi
   validateStringArgument(serviceName, 'serviceName', 'deleteDeployment');
   validateObjectArgument(callback, 'callback', 'deleteDeployment');
 
+  if (keyType.toLowerCase() !== 'primary' && keyType.toLowerCase() !== 'secondary') {
+    throw new Error('Invalid storage account type');
+  }
+
   var path = '/' + this.subscriptionId + '/services/storageservices/' + serviceName + '/keys?action=regenerate';
   var webResource = WebResource.post(path);
   webResource.withOkCode(HttpConstants.HttpResponseCodes.OK_CODE, true);