Spars matrix operations

/*A program to empelement spars matrix operations.
compiler- Turbo c++     author- Mangilal Sharma
--------------------------------------------------------*/
#include <iostream.h>
#include <conio.h>
#include <stdlib.h>

class spars
{
 private:
 int m[4][4],i,j,choice;
 public:
 void usm();
 void lsm();
 void tdsm();
 spars();
};

void spars::usm()
{
 cout<<"Enter the elements for upper sparce matrix:\n";
 for(i=0;i<3;i++)
 {
  for(j=0; j<3; j++)
  if(i<j) m[i][j]=0;
  else cin>>m[i][j];
 }
 cout<<"\n\nUpper sparce matrix is:\n";
 for(i=0;i<3;i++)
 {
  for(j=0; j<3; j++)
  cout<<m[i][j]<<"\t";cout<<"\n";
 }
}

void spars::lsm()
{
 cout<<"\n\nEnter the elements for lower sparce matrix:\n";
 for(i=0;i<3;i++)
 {
  for(j=0; j<3; j++)
  if(i>j) m[i][j]=0;
  else cin>>m[i][j];
 }
 cout<<"\n\nLower sparce matrix is:\n";
 for(i=0;i<3;i++)
 {
  for(j=0; j<3; j++)
  cout<<m[i][j]<<"\t";cout<<"\n";
 }
}

void spars::tdsm()
{
 cout<<"\n\nEnter the elements for tridiogonal sparce matrix:\n";
 for(i=0;i<4;i++)
 {
  for(j=0; j<4; j++)
  if(i<j-1||j<i-1) m[i][j]=0;
  else cin>>m[i][j];
 }
 cout<<"\n\nTridiogonal sparce matrix is:\n";
 for(i=0;i<4;i++)
 {
  for(j=0; j<4; j++)
  cout<<m[i][j]<<"\t";
  cout<<"\n";
 }
}

spars::spars()
{
 do
 {
  cout<<"\n\t\t\tSPARS MATRIX\n";
  cout<<"\t\t1. Upper sparce matrix\n";
  cout<<"\t\t2. Lower sparce matrix\n";
  cout<<"\t\t3. Tridiogonal sparce matrix\n";
  cout<<"\t\t4. To Main page\n";
  cout<<"\t\t5. To Exit from Program\n";
  cout<<"\n\t\t Enter Your Choice= ";
  cin>>choice;
  switch(choice)
  {
   case 1:
   usm();break;
   case 2:
   lsm();break;
   case 3:
   tdsm();break;
   case 4:
 return;
   case 5:
 exit(1);
   default:cout<<"\n\t\tWrong Choice, Enter Again\n";
  }
 }while(1);
}
/*=========================3Nov.,2010=============================*/