// get worksheet by name
void get_worksheet_by_name(string strName)
{
    Worksheet wks(strName);  // define worksheet by name string
    if(!wks.IsValid())  // if the worksheet is not valid
    {
        out_str("not a valid worksheet");
        return;
    }
    out_str("do something with the worksheet here");
}
// loop all worksheet page in the project, so to get worksheet by calling get_worksheet_by_name
void loop_worksheets()
{
    for(int index=0; ; index++)
    {
        WorksheetPage pg = Project.WorksheetPages(index);  // get the worksheet page in project by index
        if(!pg.IsValid())  // if page is not valid
        {
            out_str("not a valid page");
            break;  // get out of the for loop
        }
        get_worksheet_by_name(pg.GetName());  // worksheet page and worksheet share the same name in Origin 7
    }
}