  The behaviour of a driven double well Duffing-van der Pol (DVP) oscillator
for a specific parametric choice ($\mid \alpha \mid =\beta$) is studied. The
existence of different attractors in the system parameters ($f-\omega$) domain
is examined and a detailed account of various steady states for fixed damping
is presented. Transition from quasiperiodic to periodic motion through chaotic
oscillations is reported. The intervening chaotic regime is further shown to
possess islands of phase-locked states and periodic windows (including period
doubling regions), boundary crisis, all the three classes of intermittencies,
and transient chaos. We also observe the existence of local-global bifurcation
of intermittent catastrophe type and global bifurcation of blue-sky catastrophe
type during transition from quasiperiodic to periodic solutions. Using a
perturbative periodic solution, an investigation of the various forms of
instablities allows one to predict Neimark instablity in the $(f-\omega)$ plane
and eventually results in the approximate predictive criteria for the chaotic
region.
