To seek through movies or songs, use any of the following methods:
To skip forward
Click Go › Skip Forward. Alternatively, use ←.
To skip backward
Click Go › Skip Backward. Alternatively, use →.
To move to next movie or song
Click
Go › Next Chapter/Movie, or click the 
button.
To move to previous movie or song
Click
Go › Previous Chapter/Movie, or click the 
button.