tracktion- insert speed change ??

[garyw]

does anyone know how the change speed (tempo) works in tracktion.i want to know if it is neccessary to mark a region over which time the speed will be changed or if it is immediate... i wish to make mini mixes of say 7/8 songs using 2 minutes or so of each
im used to using sawplus 32,so im not sure of the best way to achieve a good beat mix in tracktion...