TextBox 當滑鼠點擊後清空默認提示文字

source : source

[ 方法一]
前台程式碼：
<div>
    <asp:TextBox ID="txtName" runat="server"></asp:TextBox>
    <asp:TextBox ID="txtPwd" runat="server"></asp:TextBox>
    <asp:Button ID="btnLongin" runat="server" Text="提交" />
</div>
後程式碼：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //用户输入
        txtName.Attributes.Add("Value", "请输入用户名");
        txtName.Attributes.Add("OnFocus", "if(this.value=='请输入用户名') {this.value=''}");
        txtName.Attributes.Add("OnBlur", "if(this.value==''){this.value='请输入用户名'}");
        //密码输入
        txtPwd.Attributes.Add("Value", "请输入密码");
        txtPwd.Attributes.Add("OnFocus", "if(this.value=='请输入密码'){this.value=''}");
        txtPwd.Attributes.Add("OnBlur", "if(this.value==''){this.value='请输入密码'}");
        //
        if (!IsPostBack)
        {
            //内容
        }
    }
}

[ 方法二]
前台文本框里添加下面2个事件属性：
OnFocus="javascript:if(this.value=='提示文字') {this.value=''}"
OnBlur="javascript:if(this.value=='') {this.value='提示文字'}"
-----------------------------------例-----------------------------------------
<asp:TextBox ID="txtName" runat="server" Text="请输入用户名"
OnFocus="javascript:if(this.value=='请输入用户名') {this.value=''}"
OnBlur="javascript:if(this.value==''){this.value='请输入用户名'}">
</asp:TextBox>

<asp:TextBox ID="txtPwd" runat="server" Text="请输入密码"
OnFocus="javascript:if(this.value=='请输入密码') {this.value=''}"
OnBlur="javascript:if(this.value==''){this.value='请输入密码'}">
</asp:TextBox>