Prime Number

Program to check prime number:-

#include<iostream.h>
#include<conio.h>

void main()
{
int n,lo,flag;
cout<<"Enter a no. to check prime or not :";
cin>>n;
for(lo=2;lo<n-1;lo++)
{
if(n%lo==0)
{
flag=1;
break;
}
}
if(flag==1)
{ cout<<endl<<n<<"is a composite number "; }
else
{ cout<<endl<<n<<" is a Prime number"; }
getch();
}