This image has already had the fireworks layered onto the black sky but the chimneys appear to be falling into the centre, as a result of using a wide angle lens and looking up at the house. We will use the perspective control in Elements 2 to change this.
Make sure you have already dragged the background image over the New Layer button at the bottom of the layers palette or unlocked the original iimage by double clicking on the original layer.
Go to Image, then Transform, then select "Perspective" from the drop down menu. Now you should be able to place the cursor on one of the square "handles" on a top corner and dag the image sideways to alter the converging verticles, Each side will move outwards by the same amount. When it looks OK you can fine tune the angles by putting the cursor on the centre top handle and dragging it to the left or right.