regex validator in asp.net

Regex Validation – Check that the value in the validated control has specific defined range. user's input is in a given range(Number or Character).  

Event will fire or control will validate only once user click on Button .

Important Property which need to handle for Regular Expression Field validation is;

ControlToValidate – Linked with id which control to validate;

EnableClientScript - specifies client-side validation is enabled or not (true/false)

Display – Contain three value None- the control is not displayed; Static - Control displays an error message if it’s not validate. Space is kept on the page for the message; Dynamic - Control displays an error message if it’s not validate. Space is not kept on the page for the message
;

Enabled - specifies whether the validation control is enabled or not(true/false)

ErrorMessage - text to display in the ValidationSummary control when validation fails, it display in validation control also

ForeColor – Text color of message

Text - message to display when validation fails

ValidationGroup – Grouping all the validation control together

@Code Snippet – Html code     Validation of phone number

   <form id="form1" runat="server">

    <div>

        <table width="60%" align="center">

            <tr>

                <td colspan="2" align="left">

                    <h1>

                        Check validation</h1>

                </td>

            </tr>

            <tr>

                <td align="right">

                    Name :

                </td>

                <td align="left">

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

                    <asp:RegularExpressionValidator ID="RegularExpressionValidator2" ControlToValidate="txtValue"

                        ValidationExpression="^([A-Za-z]{0,15})$" EnableClientScript="false" ForeColor="Red" ErrorMessage="Invalid Name!!"

                        runat="server" />

                </td>

            </tr>

            <tr>

                <td colspan="2">

                     

                </td>

            </tr>

            <tr>

                <td align="right">

                    Phone Number :

                </td>

                <td align="left">

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

                    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" Display="Dynamic" runat="server"

                        ControlToValidate="txtPhoneNumber" ForeColor="Red" ErrorMessage="Enter Phone Number !!"></asp:RequiredFieldValidator>

                    <asp:RegularExpressionValidator ID="RegularExpressionValidator1" ControlToValidate="txtPhoneNumber"

                        ValidationExpression="^(?:(?:01\d{9}|2\d{7}) ){1,}(?:01\d{9}|2\d{7})$" EnableClientScript="false" ForeColor="Red" ErrorMessage="Invalid Phone Number!!"

                        runat="server" />

                </td>

            </tr>

            <tr>

                <td colspan="2">

                     

                </td>

            </tr>

           

            <tr>

                <td colspan="2" align="center">

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

                </td>

            </tr>

        </table>

    </div>

    </form>

 In above code validating name and Validating phone number regex

@OutPut screen

Once user not enter any value in text box and click on Button;