      REAL FUNCTION gennor(av,sd) 
!********************************************************************** 
!                                                                       
!     REAL FUNCTION GENNOR( AV, SD )                                    
!                                                                       
!         GENerate random deviate from a NORmal distribution            
!                                                                       
!                                                                       
!                              Function                                 
!                                                                       
!                                                                       
!     Generates a single random deviate from a normal distribution      
!     with mean, AV, and standard deviation, SD.                        
!                                                                       
!                                                                       
!                              Arguments                                
!                                                                       
!                                                                       
!     AV --> Mean of the normal distribution.                           
!                              REAL AV                                  
!                                                                       
!     SD --> Standard deviation of the normal distribution.             
!                              REAL SD                                  
!                                                                       
!     GENNOR <-- Generated normal deviate.                              
!                              REAL GENNOR                              
!                                                                       
!                                                                       
!                              Method                                   
!                                                                       
!                                                                       
!     Renames SNORM from TOMS as slightly modified by BWB to use RANF   
!     instead of SUNIF.                                                 
!                                                                       
!     For details see:                                                  
!               Ahrens, J.H. and Dieter, U.                             
!               Extensions of Forsythe's Method for Random              
!               Sampling from the Normal Distribution.                  
!               Math. Comput., 27,124 (Oct. 1973), 927 - 937.           
!                                                                       
!                                                                       
!********************************************************************** 
!     .. Scalar Arguments ..                                            
      REAL av,sd 
!     ..                                                                
!     .. External Functions ..                                          
      REAL snorm 
      EXTERNAL snorm 
!     ..                                                                
!     .. Executable Statements ..                                       
      gennor = sd*snorm() + av 
      RETURN 
                                                                        
      END                                           
