;
;------------------------------------------------------------------
;
function fslt, slt,ut,glon,iflag
;
; If iflag = 1 -> return slt, given ut and glon
; If iflag = 2 -> return ut, given slt and glon
; If iflag = 3 -> return glon, given slt and ut
; (slt and ut always in decimal hours, glon in -180 -> 180)
;
case iflag of    
  1: begin
       fslt = ut + glon/15.
       if (fslt lt 0.) then fslt = fslt+24.
       if (fslt ge 24.) then fslt = fslt-24.
      end
  2: begin
       fslt = slt - glon/15.
       if (fslt lt 0.) then fslt = fslt+24.
       if (fslt gt 24.) then fslt = fslt-24.
     end 
  3: begin
       fslt = (slt-ut) * 15.
       if (fslt ge 180.) then fslt = fslt-360.
       if (fslt lt -180.) then fslt = fslt+360.
     end 
  else: begin    
       print,'>>> fslt: bad iflag=',iflag
       fslt = 0.
     end 
endcase
return,fslt
end