why does training returns different output values with the target sets. using backpropagation

i am learning how to build text document image extraction and recognition using backpropagation.

but my ouput training seems wasn't like what i expected.

the output wasn't similiar with my target sets at all.

the target data are:

target = zeros(1,total_images); 
target(:,[1 35 61 83 102]) = 'a';
target(:,[2 36 62 84 103]) = 'b';
target(:,[3 37 63 104]) = 'c';
target(:,[4 38 64 85 105]) = 'd';
target(:,[5 39 65 86 106]) = 'e';
target(:,[6 40 66 107]) = 'f';
target(:,[7 41 67 87 108]) = 'g';
target(:,[8 42 68 88 109]) = 'h';
target(:,[9 43 69 110]) = 'i'; 
target(:,127) = 'I';
target(:,[10 43 69 89 111]) = 'j';
target(:,[11 44 70 90 112]) = 'k';
target(:,[12 45 71 91 113]) = 'l';
target(:,[13 46 72 92 114]) = 'm';
target(:,[14 47 73 93 115]) = 'n';
target(:,[15 48 74 94 116]) = 'o';
target(:,[16 49 75 95 117]) = 'p';
target(:,[17 50 76 118]) = 'q';
target(:,[18 51 77 96 119]) = 'r';
target(:,[19 52 78 97 120]) = 's';
target(:,[20 53 79 98 121]) = 't';
target(:,21) = 'u'; 
target(:,55) = 'U'; 
target(:,[22 56 123]) = 'v'; 
target(:,[23 57 80 99 124]) = 'w';
target(:,[24 58 125]) = 'x'; 
target(:,[25 59 81 100 126]) = 'y';
target(:,[26 60 101]) = 'z'; 
target(:,37) = 0; 
target(:,28) = 1; 
target(:,29) = 2; 
target(:,30) = 3; 
target(:,31) = 4; 
target(:,32) = 5; 
target(:,33) = 6; 
target(:,34) = 7; 

but the result gives :

output =

  Columns 1 through 22

    96    95    96   113   117    95    98    98    94   107   107    98   112   112   116   114    93    92   116   111   111    95

  Columns 23 through 44

   100   110   108   110   115   104    96   106   110   101   102   113   117    96    93   110   113   111    95    98    96    94

  Columns 45 through 66

   107   112    98   112   112   111   110   112    92    93   103   105   100    93   108   116    96    93   110   113   111   111

  Columns 67 through 88

    98   107    94   107   107    98   112   112   111   110   112    92   116   103   116   108   102    93   113   111    98    98

  Columns 89 through 110

   107    95   106   117   112   111    94   115    93   103    95   111   117   115    96    93   110   113   111   111    98   107

  Columns 111 through 127

    94   107   107    98   112   112   111   110   112    92   116   103   116   100    98   108   115

instead of the target sets.

i've attached my training file (pelatihan_jst.m)

hopefully somebody would help me to solve this problem as soon as possible.

thanks before.