WaterMark Textbox using Java Script

WaterMark Textbox using Java Script : 

 JavaScript :

<script type = "text/javascript">

        var TextBoxText = "Enter Your Name";

        function WaterMark(txt, evt) {

            if (txt.value.length == 0 && evt.type == "blur") {

                txt.style.color = "gray";

                txt.value = TextBoxText;

            }

            if (txt.value == TextBoxText && evt.type == "focus") {

                txt.style.color = "black";

                txt.value = "";

            }

        }

</script>

   Name :

    <asp:TextBox ID="txtName" runat="server" Text = "Enter Your Name"

         ForeColor = "Gray" onblur = "WaterMark(this, event);"

         onfocus = "WaterMark(this, event);">

</asp:TextBox>

        <asp:Button  ID="btnSave" runat="server" Text="Save" OnClick="btnSave_Click"/>