script type="text/javascript">
var watermarkText = "輸入名稱";
function WaterMarkOnBlur(textbox) {
if (textbox.value.length == 0) {
textbox.style.color = "gray";
textbox.value = watermarkText;
}
}
function WaterMartOnfocus(textbox)
{
if (textbox.value == watermarkText) {
textbox.style.color = "black";
textbox.value = "";
}
}
/script>

asp:TextBox ID="TextBox1" runat="server" Text="輸入名稱"
ForeColor="Gray" onblur="WaterMarkOnBlur(this);"
onfocus="WaterMartOnfocus(this);">
/asp:TextBox>