TextBoxWatermark(水印文本框)控件

功能：
     可以让TextBox控件拥有水印文字。
属性：
    TargetControlID :要使用具有水印效果的TextBox控件ID。
    WatermarkCssClass :指定水印文字的CSS样式表。
    WatermarkText :显示在TextBox控件的水印文字内容。

代码实例：

     < form  id ="form1"  runat ="server" >
     < asp:ScriptManager  ID ="ScriptManager1"  runat ="server" >
     </ asp:ScriptManager >
   < asp:Panel  ID ="panIntTemp"  runat ="server"  
                            GroupingText ="新增资料" >
                             < table >
                                 < tr >
                                     < td >
                                        姓名：
                                     </ td >
                                     < td >
                                         < asp:TextBox  ID ="txtIntName"  runat ="server"   ></ asp:TextBox >
                                        
                                         < ajaxToolkit:TextBoxWatermarkExtender  ID ="tbweTxtIntName"  runat ="server"
                                            TargetControlID ="txtIntName"                                             
                                            WatermarkText ="请在此处输入姓名" >
                                         </ ajaxToolkit:TextBoxWatermarkExtender >
                                     </ td >
                                     < td >
                                        性别：
                                     </ td >
                                     < td >
                                         < asp:TextBox  ID ="txtIntGender"  runat ="server"   ></ asp:TextBox >
                                        
                                         < ajaxToolkit:TextBoxWatermarkExtender  ID ="tbweTxtIntGender"  runat ="server"
                                            TargetControlID ="txtIntGender"                                           
                                            WatermarkText ="请在此处输入性别" >
                                         </ ajaxToolkit:TextBoxWatermarkExtender >
                                     </ td >
                                 < tr >
                                     < td >
                                        出生日期：
                                     </ td >
                                     < td >
                                         < asp:TextBox  ID ="txtIntBirthday"  runat ="server"   ></ asp:TextBox >
                                        
                                         < ajaxToolkit:TextBoxWatermarkExtender  ID ="tbweTxtIntBirthday"  runat ="server"
                                            TargetControlID ="txtIntBirthday"                                            
                                            WatermarkText ="请在此处输入出生日期" >
                                         </ ajaxToolkit:TextBoxWatermarkExtender >
                                     </ td >
                                     < td >
                                        家庭住址： </ td >
                                     < td >
                                         < asp:TextBox  ID ="txtIntAddress"  runat ="server" ></ asp:TextBox >
                                       
                                         < ajaxToolkit:TextBoxWatermarkExtender  ID ="tbweTxtIntAddress"  runat ="server"
                                            TargetControlID ="txtIntAddress"                                             
                                            WatermarkText ="请在此处输入家庭住址" >
                                         </ ajaxToolkit:TextBoxWatermarkExtender >
                                     </ td >
                                 </ tr >                              
                             </ table >
                         </ asp:Panel >
     </ form >

运行结果：