The Forerunner 10 and 15 both record and display: time, distance, pace, and calories. These watches do not show or record elevation.
Both watches do record the GPS positions, (latitude/longitude) in the activity track. When uploaded,Garmin Connect will use a digital elevation model to look up the elevation for each GPS position in the track and an elevation profile will be displayed on the Activity's page.
If an elevation profile is not created, delete the activity from Garmin Connect and import the activity again from the watch.
Deleting Activities from Garmin Connect:
To manually upload using modern Connect (taken from article titled, How do I manually upload data from USB devices to Garmin Connect?):
The elevation graph should now show properly in the Activity's page.
Garmin Connect - http://connect.garmin.com/signin
How do I manually upload data from USB devices to Garmin Connect? - https://support.garmin.com/support/searchSupport/case.faces?caseId=%7Bb16302a0-02ac-11de-515b-000000000000%7D