Trouble making a chevron

Hello,
I'm trying to make a chevron for my internet explorer toolband. I have created the button like this:

CreateWindow(TEXT("button"),
NULL,
WS_CHILD | WS_VISIBLE | BTNS_WHOLEDROPDOWN | BS_BITMAP,
0, 0, LOGO_WIDTH, MENU_HEIGHT,
m_hWnd, (HMENU)ID_LOGOBUTTON,
g_hInst,
NULL);

Notice the BTNS_WHOLEDROPDOWN button style. Regardless, the button shows up but the little arrow isn't showing up. Any suggestions?

Thanks