private String GetPlaceholderText(int placeholderId, CString cs){
String text = null;
if(_ppt2007){
Sheet master = _sheet != null ? _sheet : _ppt.GetSlidesMasters()[0];
TextShape placeholder = master.GetPlaceholder(placeholderId);
if(placeholder != null) text = placeholder.GetText();
//default text in master placeholders is not visible
if("*".Equals(text)) text = null;
} else {
text = cs == null ? null : cs.GetText();
}
return text;
}
