Making a Contentbox

Pick Rectangular Marquee Tool and select a rectangle and then pick Gradient Tool (linear gradient). Pull a line from the top af your selection to the bottom. Remove the selection (ctrl + d).

Go to Blending Options - Stroke
Size: 1 px
Color: #BCBBC3

Then go to "Drop Shadow" and leave the settings...and then Inner Glow...

Hit OK

Create a new layer and pick Pen Tool. Place a point in left side of the shoutbox. Hold down Shift and make a point on the right side. Place the mouse on the middle of the line and pull downwards. Then place the two last points up in left and right corner.

Rasterize Shape 1 and set Layer-Mode to Overlay and Opacity to 50%. Pick Move Tool and place the layer in top of the shoutbox.

Activate the shoutbox-layer and Ctrl + click on the layer. Go to Select > Inverse (ctrl + shift + i) and hit Delete on your keyboard.

You are finish.