char szLongMessage[ ] =
"This is a long message for the ToolTip, which will automatically "
"be wrapped when it exceeds the maximum tip width.  "
"Alternatively, you can use a \r\n"
"carriage return/line feed combination\r\n"
"to force line breaks at specific\r\n"
"locations.";

switch (lpnmhdr->code) {
  case TTN_GETDISPINFO:
    lpttd = (LPNMTTDISPINFO)lpnmhdr;
    SendMessage(lpnmhdr->hwndFrom, TTM_SETMAXTIPWIDTH,  0 ,  300 );
    lpttd->lpszText = szLongMessage;
    return  0 ;
	
	...
 //Other notification handlers go here, as needed.