Create Web Content Box

Step1:

Create a new image 800 x 600, and change the background color to white #FFFFFF. Click Layer>New Layer or shift+Ctrl+N to create a new layer. Now click on the Rounded Rectangular tool (U) and create a rounded rectangle with the setting I have below.

If you followed the instructions you should have some thing like I have below.

Step2:

Hold CTRL and click on the layer with the rounded rectangle, this will select your rectangle. As shown in Figure 1. Create a new layer and use the Rectangular Marquee Tool to subtract from your selection until your selection looks like figure 2.

Figure 1

Figure 2

Click on the Paint Bucket tool and fill you selection with #d1d1d1.

Right click on your layer and click blending options and add the settings below.

Drop Shadow

Inner Shadow

Blend Mode color: cccccc

Inner Glow

Color: 666666

Bevel and Emboss

Gradient Overlay

Color: #cccccc ---- Color: # 666666

Stroke

When u finished entering the setting click on New Style and save the style and then click ok, you now should have something like the image below.

Step3:

Repeat step 2 and add a Footer for your content box as shown below.

Step4:

Hold CTRL and click on your rounded rectangle layer to select it. click on the Gradient Tool and apply a gradient to you selection from bottom to top as shown below.

Hold CTRL and click on your rounded rectangle layer to select it, use the subtract from selection option and subtract from you rectangle selection until you get the selection in the image below. 

create a new layer and fill you selection with #cccccc. Right click on you layer and click on Blending options and add the setting below.

Drop Shadow

Bevel and Emboss

Stroke

Gradient

Color: #cccccc ---- Color: #FFFFFF ---- Color: # 000000

After you added the setting save your style and click ok. If you did everything right you should have something like I have below.

Step5:

Now, click on your layer to select them. Hold CRTL and click on all the layers except the back ground layer, should look like the image below. Now with all the layers selected press CTRL+ E to merge the layers into one layer.

Selected Layers

Merged Layers

That is it you are finished.