Help: need a script to merge all layers, even if there is only one layer

Ok well it's been 5 years since I asked this question, forgot the answer, looked it up in 2016, and found out I asked already in 2011. Thanks again everyone!

Its aslo easy to do in an action.  Record the following

Shift+Ctrl+Alt+N (Add New Empty Layer without a prompt)

Shift+Ctrl+Alt+E (Stamp Visible Layers)

Shift+Ctrl+]         (move current layer to the front top of stack)

You need to record the first step because sometins stamp visible layers does nothing it depends what the current Photoshop target is.  When you add a new empty layer it will be added above the current Layer and become the Photoshop target and be a visible layer. You have no idea where in the stack this layer has been added.  When the curren Photoshop Target is a visble empty layer stamp visible layer will place a merge of all visible layers into that empty layer and it will still be the Photoshop Target.  To record the third step you may have to first stop recording the action add some layers and target sone layer below the top of the stack that can be moved up not the background layer. Then press the record button and use "Shift+Ctrl+]" if the current layer is the top of the stack using "Shift+Ctrl+]" will not be recorded.  I often start actions like this for doing things like sharpening.  I convert the layer to a smart object load a edge mask alpha channel as a selection then use the smart sharpen filter as a smart filter the selection get added as a filter mask. .  I then change the layers blending mode to luminosity to protect the colors and adjust the blend if gray sliders to protect the shadows and highligts more on less creates a sharpeng adjustment layer.  Which can be readjusted and adjusted via its opacity adjustment slider and you can even add a layer mask to paint away over sharpened areas.