Extract Tables from HTML page and store it in data set using Regular Expressions

Some times we need to extract information from HTML pages ,for example extracting table from HTML page
here you will find how to do it using regular expression , this code is written using C# :

private static DataSet ConvertHTMLTablesToDataSet(string HTML)
{
DataTable dt;
DataSet ds = new DataSet();
dt = new DataTable();
string TableExpression = "<table[^>]*>(.*?)</table>";
string HeaderExpression = "<th[^>]*>(.*?)</th>";
string RowExpression = "<tr[^>]*>(.*?)</tr>";
string ColumnExpression = "<td[^>]*>(.*?)</td>";
bool HeadersExist = false;
int iCurrentColumn = 0;
int iCurrentRow = 0;

MatchCollection Tables = Regex.Matches(HTML,
TableExpression,
RegexOptions.Singleline |
RegexOptions.Multiline |
RegexOptions.IgnoreCase);


foreach (Match Table in Tables)
{
iCurrentRow = 0;
HeadersExist = false;
dt = new DataTable();

if (Table.Value.Contains("<th"))
{
HeadersExist = true;

MatchCollection Headers = Regex.Matches(Table.Value,
HeaderExpression,
RegexOptions.Singleline |
RegexOptions.Multiline |
RegexOptions.IgnoreCase);

foreach (Match Header in Headers)
{
dt.Columns.Add(Header.Groups[1].ToString());
}

}
else
{

int myvar2222 = Regex.Matches(
Regex.Matches(
Regex.Matches(
Table.Value,
TableExpression,
RegexOptions.Singleline
| RegexOptions.Multiline |
RegexOptions.IgnoreCase)[0].ToString(),
RowExpression, RegexOptions.Singleline |
RegexOptions.Multiline |
RegexOptions.IgnoreCase)[0].ToString(),
ColumnExpression,
RegexOptions.Singleline |
RegexOptions.Multiline |
RegexOptions.IgnoreCase).Count;

for (int iColumns = 1; iColumns <= myvar2222; iColumns++)
{
dt.Columns.Add("Column " + System.Convert.ToString(iColumns));
}

}

MatchCollection Rows = Regex.Matches(Table.Value,
RowExpression,
RegexOptions.Singleline |
RegexOptions.Multiline | RegexOptions.IgnoreCase);

foreach (Match Row in Rows)
{

if (!((iCurrentRow == 0) & HeadersExist))
{
DataRow dr = dt.NewRow();
iCurrentColumn = 0;

MatchCollection Columns = Regex.Matches(Row.Value,
ColumnExpression,
RegexOptions.Singleline |
RegexOptions.Multiline |
RegexOptions.IgnoreCase);

foreach (Match Column in Columns)
{
dr[iCurrentColumn] = Column.Groups[1].ToString();
iCurrentColumn++;
}

dt.Rows.Add(dr);
}
iCurrentRow++;
}
ds.Tables.Add(dt);

}

return ds;
}

This code i found it through google but i converted it it C# ...