Newbie learning sorting algorithms and arrays

[peste19]

I am trying to create a program which read data and sorts it out, the data file contains id and grades of those ids and i am have to sort by order of grade and move the id with it, here is where i got so far but it is not working for me.

thanks in advance

#include <iomanip>
#include <cstdlib>
#include <iostream>
#include <fstream>

using namespace std;

int main ()
{
	int n,f,j,id[12],i;
	double grade[12],hold;
	ifstream input;

	
	for (f=0;f<12;f++)
	{
		input >> id[f];
		input >> grade[f];
	}
	for (j=0; j<12; j++)
	{
		for (i=0; i<12; i++);
		{
			 if (grade[i-1] > grade[i])
			 {
				 hold = grade[i];
				 grade [i-1] = grade[i];
				 grade[i] = hold;
			 }
			 cout << grade[i] << "\n";
		}
	}
	input.close();
	system ("pause");
	return 0;
}