correct this code

[doraid]

the home work said that:

Write c++ program that prompts the user to enter numaric values for a 4X 4 array.
the program will display the fllowing menu.
1-Is magic?
2-Sorter
3-diagonal summation
4-Exit

-Is magic wil determine if arry is magic or not.
-Sorter will sort the array values in ascending order
-Diagonal summation will determine the some of two diagonal in the array.
-Exit: to exit from program.



and done my best to do this:
# include<stdio.h>
#include<iostream>
#include<conio.h>
using namespace std;

#define NR_ROW 4
#define NR_COL 4

int main()
{
int ary_elmnt, i, j, choose, colsum[4],rowsum[4];
int diagsum[2]={0};
float mat[NR_ROW][NR_COL];

for (i = 0; i < NR_ROW; i++)
{
for (j = 0; j < NR_COL; j++)
{
cout<<"\n Please Enter The Array Elements (16 Numbers): ", i, j;
cin>> mat[i][j];
}
}

/* **************************************************** */
system("cls");
cout<<"\n The Array Elementa Are:\n\n";
for(i=0;i<NR_ROW;++i)
{
for(j=0;j<NR_COL;++j)
cout<<mat[i][j]<<"\t";
cout<<"\n ";
}
/* **************************************************** */

cout<<"\n 1- Is The Array (Magic Square)?\n";
cout<<"\n 2- Summation of Tow Diagonals\n";
cout<<"\n 3- Sorter?\n";
cout<<"\n 4- EXIT\n";


/* **************************************************** */

do{
cout<<" Please Choose Your Choice: ";
cin >> choose;

switch (choose)
{
case 1 : isMagic(); break;
case 2 : cout << " Sorter\n"; break;
case 3 : for (i=0; i<NR_ROW; ++i) {
colsum[i]=0;
rowsum[i]=0;
for (j=0; j<NR_COL; ++j) {
rowsum[i]+=mat[i][j];
colsum[i]+=mat[i][j];
}
diagsum[0]+=mat[i][i];
diagsum[1]+=mat[NR_COL-i-1][i];

}
cout <<"The diagonals summation is"<<diagsum[1];

case 4 : exit(1);
default: cout << "\n SORRY,This Number ( " << choose << " ) Does Not Exist On The Menu, Please Try Again.\n\n";

}

}while (1);


system ("pause");
return 0;

}

int isMagic( int n, int mat[NR_ROW][NR_COL]) {

int colsum[NR_ROW];
int rowsum[NR_COL];
int diagsum[2]={0};

// calculate row, column, and diagonal sums
for (int i=0; i<NR_ROW; ++i) {
colsum[i]=0;
rowsum[i]=0;
for (int j=0; j<NR_COL; ++j) {
rowsum[i]+=mat[i][j];
colsum[i]+=mat[i][j];
}
diagsum[0]+=mat[i][i];
diagsum[1]+=mat[NR_COL-i-1][i];
}


int testSum=(1+NR_COL*NR_COL/2)*NR_COL;

// check to see if all sums are equal to testSum
int zeroIfNotMagic=1;
for (int i=0; i<n; ++i) {
// test row sum
if ( rowsum[i]!=testSum ) {
zeroIfNotMagic=0;
break; }

// test column sum
if ( rowsum[i]!=testSum ) {
zeroIfNotMagic=0;
break;
}
}

// test diagonal sums
for (int i=0; i<2; ++i) {
if ( diagsum[i]!=testSum ) {
zeroIfNotMagic=0;
break;
}
}

// return 0 if the square is not "magical", 1 if it is.
return zeroIfNotMagic;
}