Convert Text in TextBox to LowerCase and UpperCase When User Typing Using Javascript

There are scenarios where we should allows users to type in only upper case characters or a lower case characters in a textbox. It will be good if we automatically do this conversion when the user types in using Javascript.

The below Javascript function will help us to do that.

<script language="javascript">

    function ToUpper(ctrl)

    {  

    var t = ctrl.value;

    ctrl.value = t.toUpperCase();

    }

    function ToLower(ctrl)

    {  

    var t = ctrl.value;

    ctrl.value = t.toLowerCase();

    }

    </script>

<asp:TextBox ID="txtName" onkeyup="ToUpper(this)" runat="server"></asp:TextBox>

<asp:TextBox ID="TextBox1" onkeyup="ToLower(this)" runat="server"></asp:TextBox>