VC++ programmatically scroll down in listview

[vicky_menonsky]

iSel = ListView_GetSelectionMark(g_hwndLV);

//used to get cursor selection from list view &then we write it to file
//i hav problems moving the slection to next item .currently am using follg code:

index=ListView_GetNextItem(g_hwndLV,-1,LVNI_BELOW);

iSel=ListView_SetSelectionMark(g_hwndLV,index);

//and then i write code to write next selected entry into file .code compiles.but doesnt work as expected.
//else could i get source code for scrolling down &selecting an item!

plzzzz help!