static void ValidateHeaderRow(_Worksheet sheet)
{
ValidateString(SurnameHeaderColumn, sheet.GetTextFromRange("A1"));
ValidateString(ForenameHeaderColumn, sheet.GetTextFromRange("B1"));
ValidateString(CoursenameHeaderColumn, sheet.GetTextFromRange("C1"));
ValidateString(SexHeaderColumn, sheet.GetTextFromRange("D1"));
ValidateString(YearofbirthHeaderColumn, sheet.GetTextFromRange("E1"));
}