program to find the sum of diagonal elements of the matrix

#include<iostream.h>
#include<conio.h>
void main()
{
 clrscr();
 int x[10][10],m,n,sum=0;
 cout<<"number of rows and columns"<<endl;
 cin>>m>>n;
 for(int i=0;i<m;i++)
  for(int j=0;j<n;j++)
  {
   cin>>x[i][j];
   if(i==j)
   sum+=x[i][j];
   }
  cout<<"sum of diagonal elements: ";
  cout<<sum;
  getch();
  }