DHC-8-100 flight crew experienced a loss of hydraulic quantity in the number two hydraulic system. An emergency was delcared followed by an uneventful landing.

Narrative

To the best of my memory; the Captain took off the runway and upon gear retraction we received 3 amber gear door open advisory lights; green; amber; and red nose gear lights; an amber gear in-transient light; and associated master caution lights with loss of #2 system hydraulic contents and pressure including #2 ENG HYD PUMP; RUD PRESS; RUD FULL PRESS; #2 RUD HYD; and intermittent ROLL SPLR OUTBD HYD; excluding #2 HYD ISO VLV lights. Loss of #2 system hydraulic contents and pressure was verified and we continued straight out to 2;000 FT and started performing the after takeoff checklist while keeping airspeed below 140 KTS. Our departure airport Operations were notified and we were instructed to proceed to another airport (ZZZ) by our Dispatcher. An emergency was declared and Approach started vectors to ZZZ. Meanwhile; the #2 ENG HYD PUMP with zero quantity checklist was performed to the best of our ability and judgment. The flight attendant; passengers; and ZZZ Operations were notified of our intentions and were also briefed thoroughly of our circumstances. We were soon cleared for the ILS into ZZZ and performed an alternate gear extension. We landed safely in ZZZ where fire/rescue crew did a complete inspection and verified no abnormalities. We continued to taxi to the gate and parked. Immediately upon engine shutdown I installed all gear pins and the passengers were then deplaned and escorted. All passengers were pleased and extended great gratitude for our efforts.