ListView_SubItemHitTest failure

[manjut19]

Hi all,
I used ListView_SubItemHitTest in my win32 application to get hit test information about my list control.But its returning -1.What will be the reason.Code given below.

x=(long)LOWORD(lParam);
y=(long)HIWORD(lParam);
LVHITTESTINFO ItemClicked;
ZeroMemory(&ItemClicked, sizeof(ItemClicked));
ItemClicked.pt.x=x;
ItemClicked.pt.y=y;
ItemClicked.flags=LVHT_ABOVE|LVHT_NOWHERE;
int iResult=ListView_SubItemHitTest(hwnd,&ItemClicked);