Binary Search Using Function In Turbo C++

/*Made By-Mohd Mujtaba , Tested On-Turbo C++*/
#include<iostream.h>
#include<conio.h>
#include<stdlib.h>

int num[5],num1,beg,last,mid;
int size;

void main()
{
 clrscr();
 cout<<"Enter The Size Of Array ";
cin>>size;
 cout<<"Enter The Number In Array ";
for(int i=0;i<size;i++)
cin>>num[i];
cout<<"Enter The Number To Be Searched For ";
cin>>num1;
last=size-1;
int bsearch(void);
int index;
index=bsearch();
if(index==-1)
cout<<"Not Found";
else cout<<"Found At"<<index;
}
int bsearch()
{
while(beg<=last)
{
mid=(beg+last)/2;
if(num1==num[mid])
return mid;
else
    if(num1>num[mid])
    beg=mid+1;
    else if(num1<num[mid])
    last=mid-1;

 }
 return -1;
 }