urgent please help with this code . for modulation ask . vactorize

 keep getting an error 
((Matrix dimensions must agree.
modulated = bw.*carrier

Error in Ask (line 19) modulated = bw.*carrier ;)) what should i do ? to make this code work ? i marked in bold the line that is causing the trouble . modulated = bw.*carrier

here is the code

if true
  % code
end((clc;
clear all;
close all;

      b = input ('Enter The Bit Stream\n'); % B is the binary Bit stream 
      fc = input ('carrier Frequency='); % F is the frequency carrier 
      n = length(b); 
      t = 0:.1:n;
      x = 1:1:(n+1)*100;

      for i = 1:n 
          for j = i:.1:i+1
              bw(x(i*100:(i+1)*100)) = b(i);
          end
      end
      bw = bw(100:end);
      carrier = cos(2*pi*fc*t);
      * * __modulated = bw.*carrier_*_* ;
      subplot(3,1,1)
      plot(t,bw)
      grid on ;
      ylable('amplitude')
      xlabel('time')
      title('message signal')
      subplot(3,1,2)
      plot(t, carrier) 

      grid on ;

      ylabel( 'amplitude')
      xlabel( 'time')
      title ( 'carrier signal')
      subplot(3,1,3)
      plot(t,modulated)

      grid on ;

      ylabel( 'amplitude')
      xlabel( 'time')
      title ( 'modulated Signal')
))

close all;