Textbox pe special character ka validation lagaye ajaxtoolkit k thru

 <%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajaxtoolkit" %>

<asp:TextBox ID="TextBox7" runat="server" ClientIDMode="Static" Width="220px" MaxLength="50"></asp:TextBox>

<ajaxtoolkit:FilteredTextBoxExtender

    ID="FilteredTextBoxExtender6"

    runat="server"

    TargetControlID="TextBox7"

    FilterType="Custom"

    FilterMode="InvalidChars"

    InvalidChars="!@#$%^&*()_+[]{}|;':,.\<>?=`~" />