HELP:::MIX numbers in array

I am doing a hw assignment which is a puzzle game and i came to this problem.

I have a 2d array and i have a set of numbers lets say (ex:1-100)

I need to place these numbers randomely in the array.

I initially tried to user srand() and rand() to fill the array with numbers upto 100 but it repeat numbers some times. so it doesn't work.

This is what I have now. Thankx in advance guys. have a good day

Code:

for (i=0;i<need_num;i++)

{

srand(i);

b=rand()%need_num; // random number with in need_num

//temp storing the rand # in a array temp

temp_array[i]=b;

}

i=0;

//filling actual array, we leav the emptyspaces as 0's at the end of the

//array

for(n=0;n<dim;n++){

for(m=0;m<dim;n++){

array[n][m]=temp_array[i];

i++;

}

}

}