Program Menghitung Total Penjualan Dan Bonus Karyawan

#include <iostream.h>
#include <conio.h>
#include <iomanip.h>
void main(){
int a=1,data,i;
char nama_sales[100];
double totpen, bonus;

cout<<"masukan banyak sales : " ;cin>>data;
for(i=1;i<=data;i++)
    {cout<<endl;
     cout<<"nama sales      : " ;cin>>nama_sales[i];
     cout<<"total penjualan : " ;cin>>totpen;
     cout<<endl;
    }

cout<<endl;
    cout<<"_______________________________________"<<endl;
    cout<<"No  Nama sales         total penjualan"<<endl;
    cout<<"_______________________________________"<<endl;
for (i=0;i<=data;i++) {

    cout<<" "<<a++<<setw(8)<<nama_sales[i]<<setw(19)<<totpen<<endl;

}   cout<<"_______________________________________"<<endl;
cout<<endl;
    if (totpen>=5.000000){
    cout<<"bonus = 500.000";
    }
    else if ((totpen=4.000000)&&(totpen<5.000000)){
    cout<<"bonus = 500.000";
    }
     else if ((totpen=3.000000)&&(totpen<4.000000)){
    cout<<"bonus = 400.000";
    }
     else if ((totpen=2.000000)&&(totpen<3.000000)){
    cout<<"bonus = 300.000";
    }
     else if ((totpen=1.000000)&&(totpen<2.000000)){
    cout<<"bonus = 200.000";
    }
    cout<<endl;
    cout<<"_______________________________________"<<endl;
    cout<<"No  Nama sales                 bonus "<<endl;
    cout<<"_______________________________________"<<endl;
for (i=1;i<=data;i++) {


    cout<<" "<<a++<<setw(8)<<nama_sales[i]<<setw(19)<<bonus<<endl;

}   cout<<"_______________________________________"<<endl;
getch();
}