Simplest thing ever

There is probably already a tutorial (if not five or six) for this, but I was unsure which category to look in. I tried borders but that wasn't what I wanted. What I want to know is this. I know that you can create a square or a rectangle that's filled with color by using the rectangle tool. What I want to know how to do is how to create a square or a rectangle that is NOT filled with color but instead bordered by color. Basically a transparent box bordered in some color. If this isn't possible, I could do a white box that is bordered in color. I'm using PS7. If you could help me out here, I'd really appreciate it. It's for an important project!