integration question



Hello, my question is about symbolic integration. Can maxima solve the 
integral if the output can be given it terms of special functions? May 
be some additional package must be used for it? For expample maxima can 
not give answer for this integral:
(%i1) integrate(exp(a*sin(phi)),phi,0,2*%pi);
                             2 %pi
                            /
                            [           a sin(phi)
(%o1)                  I      %e                    dphi
                            ]
                            /
                             0
(%i2)

Mathematica can solve it:

integrate(exp(a*sin(phi)),phi,0,2*Pi)

output:

2 Pi BesselI[0, a]