the window :
When a sample has been loaded or generated, it is then displayed within its own window. Size and position can be changed via the windows gadgets. Several lines are drawn to help reading positions and levels of the sample. Additional lines can be drawn to display the maximum, average and real (acoustical) amplitude.
If 'Loop' is activated and start and repeat lengths are set, vertical lines with boxes attached to the top will visualise the looping part. If some range is selected (marked), this is shown by an highlighted filled box.
In the window titlebar SFX displays the samples name, playbackrate and length. While playing a sample you see the play-position there.

actions inside the window :
When moving the mouse around the mousepointer will change its shape to indicate what action can be performed.
The looplines can be moved by clicking and holding the left mousebutton onto the box and moving the mouse.
Clicking down the left mousebutton inside the sample window but outside of the loop boxes or a peviously marked area will start a new marking operation. When clicking inside a mark (not near the borders), it can be moved around, while holding the left mousebutton. When clicking inside a mark at the borders, the range can be modified into that direction. Here is a 'picture' to make it more clearly (anyway the mouse pointer shape shhould cleary show the availabe action) :