I agree with @Dark Tranquility ;. Maybe @webcosmo ; knows what you mean but I don't know what you mean. I can only suggest that you make sure that your layer is not locked.
Before asking, do a search... if you don't find the answer, then ask The purpose of this forum is to help others in the community, that's why it's called Sitepoint and not Linkpoint. SP Guidelines - No fluff.
You can either double click the image in the layers panel. Or you can go to layer -> new -> layer from background and then name your new layer and click ok (same thing happens when you double click layer in the layers panel).