Spell Checking Multiple Fields in ASP.Net

ASPX Source Code

SourceCode:
<%@ Register Assembly="ASPNetSpell" Namespace="ASPNetSpell" TagPrefix="ASPNetSpell" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
             <asp:TextBox ID="SpellTextBox1" runat="server">...</asp:TextBox>
             <asp:TextBox  ID="SpellTextBox2" runat="server">...</asp:TextBox>
             <asp:TextBox ID="SpellTextBox3" runat="server">...</asp:TextBox>

        <ASPNetSpell:SpellButton ID="SpellButton1" runat="server" />
    </div>
    </form>
</body>
</html>