I have seen the application article about function pointer, but after I have use the OVERLAY attribute, the link told me that :Invalid Keyword. In a osddrive.c file, I create an array like below: code void(code *maincursordraw[])()={drawinputmenu}; Function drawinputmenu() has been in the same file. The function is called in another function WriteMainMenu() like below:(*MainCursorDraw[bxMainCursor])(); The link in my project is: BL51 @D3link.lin A part of file D3link.lin is: BANK1 { Icon.obj, OsdCtrl.obj, OsdWrite.obj, OsdTable.obj, OsdDrive.obj overlay(?co?osddrive~drawinputmenu), OsdUtil.obj, gccduser.obj, basechar.obj}, Why the link program told me Invalid Keyword????