js 的checkbox 全选

<% ... @ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default"  %>

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >

< html  xmlns ="http://www.w3.org/1999/xhtml"   >
< head  runat ="server" >
     < title > 无标题页 </ title >
     < script  type ="text/javascript" > ...  
// 说明：Javascript 控制 CheckBox 的全选与取消全选 // 整理：http://www.CodeBit.cn 

 function checkAll(name)
  ...{    
 
      var el = document.getElementsByTagName('input');   
      var len = el.length;     
      for(var i=0; i<len; i++)    
      ...{         
         if((el[i].type=="checkbox") && (el[i].name==name))      
            ...{          
               el[i].checked = true;         
             }   
               
        } 
    }
     
    function clearAll(name)
    ...{   
        var el = document.getElementsByTagName('input');    
        var len = el.length;    
        for(var i=0; i<len; i++)   
        ...{  
            if((el[i].type=="checkbox") && (el[i].name==name))      
             ...{  
                   el[i].checked = false;       
             }   
        } 
            
     } 
     </ script >  
</ head >
< body >
     < form  id ="form1"  runat ="server" >
     < div >
      < input  type ="checkbox"  name ="test"  value =""  onclick ="if(this.checked==true) { checkAll('test'); } else { clearAll('test'); }"   />  字母全选开关 
      < input  type ="checkbox"  name ="test"  value ="a"   />  a 
      < input  type ="checkbox"  name ="test"  value ="b"   />  b 
      < input  type ="checkbox"  name ="test"  value ="c"   />  c 
      < input  type ="checkbox"  name ="test"  value ="d"   />  d
       < input  type ="checkbox"  name ="test"  value ="e"   />  e
        < input  type ="checkbox"  name ="test"  value ="f"   />  f
         < input  type ="checkbox"  name ="test"  value ="g"   />  g  
         < br  />   
         < input  type ="checkbox"  name ="num"  value =""  onclick ="if(this.checked==true) { checkAll('num'); } else { clearAll('num'); }"    />  数字全选开关 
         < input  type ="checkbox"  name ="num"  value ="1"   />  1  < input  type ="checkbox"  name ="num"  value ="2"   />  2 
         < input  type ="checkbox"  name ="num"  value ="3"   />  3   < br  />
         < br  />   
         < input  type ="button"  value ="选择所有的字母"  onclick ="checkAll('test')"   />  
         < input  type ="button"  value ="清空选中的字母"  onclick ="clearAll('test')"   /> &nbsp; < br  />
         < br  />  
          < input  type ="button"  value ="选择所有的数字"  onclick ="checkAll('num')"   />  
          < input  type ="button"  value ="清空选中的数字"  onclick ="clearAll('num')"   />   
         < asp:CheckBox  ID ="CheckBox1"  runat ="server"   />< br  />
     </ div >
         < div  style ="width: 100px; height: 100px" >
             < asp:GridView  ID ="GridView1"  runat ="server"  Font-Size ="10pt"  Height ="215px"  Width ="698px"  DataKeyNames ="id" >
                 < Columns >
                     < asp:TemplateField >
                         < ItemTemplate >
                             < input  id ="ckOne"  type ="checkbox"  name  ="test"   />
                         </ ItemTemplate >
                     </ asp:TemplateField >
                 </ Columns >
             </ asp:GridView >
             < asp:Button  ID ="Button1"  runat ="server"  OnClick ="Button1_Click"  Text ="删除"   /></ div >
     </ form >
</ body >
</ html >