Convert HTML Table to DataSet in Asp.Net

private DataSet ConvertHTMLTablesToDataSet(string HTML)

    {

        // Declarations 

        DataSet ds = new DataSet();

        DataTable dt = null;

        DataRow dr = null;

        DataColumn dc = null;

        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;

        // Get a match for all the tables in the HTML 

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

        // Loop through each table element 

        foreach (Match Table in Tables)

        {

            // Reset the current row counter and the header flag 

            iCurrentRow = 0;

            HeadersExist = false;

            // Add a new table to the DataSet 

            dt = new DataTable();

            //Create the relevant amount of columns for this table (use the headers if they exist, otherwise use default names) 

            if (Table.Value.Contains("<th"))

            {

                // Set the HeadersExist flag 

                HeadersExist = true;

                // Get a match for all the rows in the table 

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

                // Loop through each header element 

                foreach (Match Header in Headers)

                {

                    dt.Columns.Add(Header.Groups[1].ToString());

                }

            }

            else

            {

                for (int iColumns = 1; iColumns <= Regex.Matches(Regex.Matches(Regex.Matches(Table.Value, TableExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase)[0].ToString(), RowExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase)[0].ToString(), ColumnExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase).Count; iColumns++)

                {

                    dt.Columns.Add("Column " + iColumns);

                }

            }

            //Get a match for all the rows in the table 

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

            // Loop through each row element 

            foreach (Match Row in Rows)

            {

                // Only loop through the row if it isn't a header row 

                if (!(iCurrentRow == 0 && HeadersExist))

                {

                    // Create a new row and reset the current column counter 

                    dr = dt.NewRow();

                    iCurrentColumn = 0;

                    // Get a match for all the columns in the row 

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

                    // Loop through each column element 

                    foreach (Match Column in Columns)

                    {

                        // Add the value to the DataRow 

                        dr[iCurrentColumn] = Column.Groups[1].ToString();

                        // Increase the current column  

                        iCurrentColumn++;

                    }

                    // Add the DataRow to the DataTable 

                    dt.Rows.Add(dr);

                }

                // Increase the current row counter 

                iCurrentRow++;

            }

            // Add the DataTable to the DataSet 

            ds.Tables.Add(dt);

        }

        return ds;

    }

Remove html tags from string in Asp.net

  public static string StripHtml(string html, bool allowHarmlessTags)

    {

        if (html == null || html == string.Empty)

            return string.Empty;

        if (allowHarmlessTags)

        {

            return System.Text.RegularExpressions.Regex.Replace(html, "", string.Empty);

        }

        return System.Text.RegularExpressions.Regex.Replace(html, "<[^>]*>", string.Empty);

    }

Email Validation in ASP.net

protected  bool EvaluateIsValid()

    {

        string val = txtEmail.Text;

        string pattern = @"^[a-z][a-z|0-9|]*([_][a-z|0-9]+)*([.][a-z|0-9]+([_][a-z|0-9]+)*)?@[a-z][a-z|0-9|]*\.([a-z][a-z|0-9]*(\.[a-z][a-z|0-9]*)?)$";

        Match match = Regex.Match(val.Trim(), pattern, RegexOptions.IgnoreCase);

        if (match.Success)

            return true;

        else

            return false;

    }

Disable copy paste in asp.net textbox

<asp:TextBox ID="TextBox1" runat="server"

oncopy="return false"

onpaste="return false"

oncut="return false">

</asp:TextBox>

Disable Right Click -Asp.Net

<script language="JavaScript">

      // on right click appear this message

      var DisplayMsg="Right Click Disabled";

      //return message

      function clickBYIE()

      {

          if(document.all)

          {

              alert(DisplayMsg);

              return false;

          }

      }

      //return message

      function clickBYNS(e)

      {

          if (document.layers||(document.getElementById&&!document.all))

          {

              if (e.which==2||e.which==3)

              {

               alert(DisplayMsg);

               return false;

              }

          }

      }

     //set the function as per browser

      if (document.layers)

      {

          document.captureEvents(Event.MOUSEDOWN);document.onmousedown=clickBYNS;

      }

      else

      {

          document.onmouseup=clickBYNS;document.oncontextmenu=clickBYIE;

      }

      //disabled the right click on the browser

       document.oncontextmenu=new Function("return false")

  </script>

Set Default Button in ASP.NET

<form id="form1" runat="server" defaultbutton="Button1">

   <asp:TextBox ID="Textbox1" runat="server" />

   <asp:TextBox ID="Textbox2" runat="server" />

   <asp:Button ID="Button1" runat="server" Text="Submit" />

   <asp:Button ID="Button2" runat="server" Text="Cancel" />

</form>