function bfldlal(z)    
C   
C---Calcul du champ b en z    
C   
c-----------------------------------------------------------------------
c   Nouvelle version utilisant les fonctions SPLINE
c-----------------------------------------------------------------------
c
      include 'param_sz.h'
      include 'debug.h'
      include 'ucom.h'
c
      common/spline/c(nsplc),zchp(nspl),chp(nspl),ivrai
      dimension v(5)    
      v(1)=z    
c   
c---interpolation spline    
c   
      call spln2(ivrai,zchp,chp,c,v) 
      bfldlal=v(2)
      if(v(5).lt.2. .or. v(5).gt.2.) bfldlal=0.
      return    
      end   
c++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*