JavaScript实现表格复选框全选与反选功能

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 
<title>Table中的CheckBox</title> 
<script type="text/javascript" src="script/jquery-1.10.1.js"></script> 
<style type="text/css"> 
  body 
  { 
   width:100%; 
   height:100%; 
   font-size:12px; 
  } 
  table 
  { 
   width:80%; 
   height:100%; 
  } 
  .tr_odd 
  { 
   background: #EBF2FE; 
  } 
  .tr_even 
  { 
   background: #B4CDE6; 
  } 
  .tab_body 
  { 
   text-align: center; 
  } 
</style> 
<script type="text/javascript"> 
  $(function(){ 
    $("tr:odd").addClass("tr_odd");//奇数行背景色 
    $("tr:even").addClass("tr_even");//偶数行背景色 
     
    $("#ckb_head").click(function(){ 
      if($(this).prop("checked")){//全选 
        $("input[name='ckb']").attr("checked","true"); 
      }else{//全不选 
        $("input[name='ckb']").removeAttr("checked"); 
      } 
    }); 
  }); 
   
  //部分选 
  function ckbSome(){ 
    var flag = true; 
    var selectedCkb = document.getElementsByName("ckb"); 
    for(var i=0;i<selectedCkb.length;i++){ 
      if(selectedCkb[i].checked == false){ 
        flag = false; 
      } 
      if(flag){ 
        document.getElementsByName("check_box")[0].checked=true; 
      }else{ 
        document.getElementsByName("check_box")[0].checked=false; 
      } 
    } 
  } 
</script> 
</head> 
<body> 
  <table> 
   <tr style="background: #CCCCCC;text-align: center;"> 
    <th><input type="checkbox" id="ckb_head" name="check_box"/></th> 
    <th>学号</th> 
    <th>姓名</th> 
    <th>年龄</th> 
    <th>性别</th> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060101</td> 
    <td>张华</td> 
    <td>23</td> 
    <td>男</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060102</td> 
    <td>赵雪</td> 
    <td>24</td> 
    <td>女</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060103</td> 
    <td>孙旭</td> 
    <td>21</td> 
    <td>男</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060104</td> 
    <td>李姝</td> 
    <td>20</td> 
    <td>女</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060105</td> 
    <td>公孙旭</td> 
    <td>22</td> 
    <td>男</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060106</td> 
    <td>李枝花</td> 
    <td>24</td> 
    <td>女</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060107</td> 
    <td>魏征</td> 
    <td>22</td> 
    <td>男</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060108</td> 
    <td>施礼</td> 
    <td>20</td> 
    <td>女</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060109</td> 
    <td>王志</td> 
    <td>23</td> 
    <td>男</td> 
   </tr> 
   <tr class="tab_body"> 
    <td><input type="checkbox" name="ckb" onclick="ckbSome()"/></td> 
    <td>2013060104</td> 
    <td>方小许</td> 
    <td>20</td> 
    <td>女</td> 
   </tr> 
  </table> 
</body> 
</html>