HSA

This was our 1st year having an HSA account. We received Form 1099-SA showing our distributions for medical expenses we paid for. But my husbands W-2 does not show anything in box 12 with a W to show how much we put into the HSA. Instead his company just deducted it from his wages in Box 1. What do I do? I don't know how to fill out form 8889. Please help. Do I need to request a correted W-2?