给密码框赋值

<asp:TextBox ID="txtNotePwd" runat="server" TextMode="Password"  Width="152px"></asp:TextBox>

protected void Page_Load(object sender, EventArgs e)    {        if (!IsPostBack)        {            this.txtNotePwd.Attributes.Add("value", "123");                }        } 

清空密码框value值

protected void btnDele_Click(object sender, EventArgs e)    {        try        {            systemSet.OutPutStartupScript("alert('" + msg + "');document.getElementById('txtNotePwd').value='';");        }        catch (Exception err)        {        }    }