Now my program doesn't know "cout".

Here's my code:

Code:
// hello_world.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>

int _tmain(int argc, _TCHAR* argv[])
{
	cout << "Hello World!";
}

And error:

Code:
1>------ Build started: Project: hello_world, Configuration: Debug Win32 ------
1>Compiling...
1>hello_world.cpp
1>c:\plugins\srcds\beta\hello_world\hello_world\hello_world.cpp(9) : error C2065: 'cout' : undeclared identifier
1>Build log was saved at "file://c:\Plugins\srcds\beta\hello_world\hello_world\Debug\BuildLog.htm"
1>hello_world - 1 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
I included the <iostream> in the main file. Didn't work.

I also added the resource.o to resources.

It said "unknown rules" - I just ran throught and it worked.(I hope)