overriding manipulator endl

[kakalake]

How can i override the manipulator endl. I tried the following thing:

#include<iostream>

inline ostream& std::endl( ostream& os )
{
  os << "\n\n\n" << flush;
  return os;
}

void main(void)
{
  cout << "hallo" << std::endl;
}

But it doesen´t work. Why? It should. I thing i have some problem with the namespace, maby.

Thanks in advance