How to disable the close button of console using C

The code for making the close button  disabled is given below. It disables the close button and hence user cannot close console. But one can close console using Task Manager.

#define _WIN32_WINNT 0x0500

#include 

#include 

int main(int argc, _TCHAR* argv[])

{

    HWND h;

    HMENU sm;

    int i, j, c;

    LPTSTR buf;

    // get the handle to the console

    h = GetConsoleWindow();

    // get handle to the System Menu

    sm = GetSystemMenu(h, 0);

    // how many items are there?

    c = GetMenuItemCount(sm);

    j = -1;

    buf = (TCHAR*) malloc (256 *sizeof(TCHAR));

    for (i=0; i

        // find the one we want

        GetMenuString(sm, i, buf, 255, MF_BYPOSITION);

        if (!strcmp(buf, "&Close")) {

            j = i;

            break;

        }

    }

    // if found, remove that menu item

    if (j >= 0)

        RemoveMenu(sm, j, MF_BYPOSITION);

    return 0;

}