再线急，请帮忙调个if else 错误？

Question

for i:=1 to headno do
                  begin          //1                    read(f1,ch);
                    s:=integer(ch);
                      if(s<>30) then
                          begin    //2
                           ziduan:=ziduan+ch;                           end    //end 2
                        else
                           begin  // 3                            three:=copy(ziduan,1,3);
                             last:=copy(ziduan,1,length(ziduan));
                                if (strcomp(Pchar(three),Pchar(s1))=0)
                                  then
                                    begin     //4
                                      for j:=1 to length(last) do
                                         begin   // 5
                                           one:=copy(last,j,1);
                                           if(integer(one)<>31)
                                             then
                                             zzduan:=zzduan+one;
                                               else
                                              begin   // 6
                                   kanbiao:=copy  (zzduan,1,1);
                            kanname:=copy(zzduan,2,length(zzduan)-1);
                            if(strcomp(pchar(kaobiao),pchar('a'))=0)
                                    then
                                    write(f2,kanname);
                                                  
                                    end   // end 6
                                 end;    // end 5
                            end;     //end 4                           ziduan:='';
                          end;    //end 3
                   end; //end 1