FUNCTION :  ETA[cuspORD] -  Computes the order at a cusp z 
                            with respect to the group G= GAMMA_0(N) 
                            of the given etaproduct 

CALLING SEQUENCE :  cuspORD()                                      
                    cuspORD(etaprod,N,cusp)                                      

PARAMETERS :
   etaprod - eta-quotient                                    
   N       -  postive integer                                  
   cusp    -  rational                                          
                  -            

GLOBAL VARIABLES : 

SYNOPSIS :   
   Computes the order at a cusp z with respect to the group 
   G= GAMMA_0(N) of the given etaproduct f; ie. ORD[G](f,z) 

EXAMPLES :   

DISCUSSION :

SEE ALSO :