I Need Help Jumping My Horse Please!!!!!!!!!!!?

Ok, so my horse was a great jumper with her first owners, but her second owners didn't jump her for 4 years. now i own her i want to start jumping her again. i have lead her over poles and shes calm about that and have lunged her over a tiny cross-rail. when i go to ride her over them she gets nervous, puts her head up, prances on the spot, tries to avoid the jump and if i push her over it she rushes towards it and gallops after it. what can i do??????? Points to best answer.