cout not declared

[gipsycr]

Hello. I really appreciated if you can help me with this situation.
In Code::Blocks 13.12, I am trying to run the below code from Dev-C++4.9.92. That means a code running in Dev-C++4.9.92 cannot be ran in Code::Blocks 13.12.Could you tell if there is a way to fix such errors? I included infra one of the messages displayed in Logs & Others window:

#include <iostream>
#include <conio.h>
main() {
int counter;
counter=0;
while(counter<5) {
cout<<"\nInstruction"<<counter<<" ";
counter=counter+1;
}
getch();
}

main.cpp|9|error: 'cout' was not declared in this scope.

[Chriscpp]

std::cout<<"\nInstruction"<<counter<<" ";

[gipsycr]

Your suggestion works perfect. Many thanks.
In the book I’m using (C How to program 2/Ed) I cannot find the use of std::cout. However, I found the use in “http://msdn.microsoft.com/en-us/library/aewtdfs3.aspx” , but I don’t understand.