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 <stdio.h>
#include <windows.h>
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<c; 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;
}