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>