Locked Layers

I am very new to photoshop and have a question that I hope has an easy fix. I am trying simply to work with layers, however when I start a new document and then import a photo, the background automatically locks. The lock icon is visible in the layers pallate. I can drag that icon to the trash and import another photo but the first photo disapears as the layers all merge on top of one another and the lock icon returns. Please help! Thank you so much!

Hello,
The background layer is always locked. However, you may unlock it by converting to regular layer (pull down "Layer > New > Layer from Background" or just double-click it's name in the Layers palette)

After much headache and removing and installing ps more than once, I finally realized that I had to click the "restore down" button after opening the second image. Rookie mistake!