javascript的DOM学习上

<!doctype html>
<html>
    <head>
        <meta charset="utf-8"/>
    </head>
    <body>

        <script>
            for(var i=0;i<10;i++)
            {

            document.write("<li><input type='checkbox' name='select[]'>"+i+"aaaaaaaaaaaaaaaaaa</li>")
        }
    
        
        var select=document.getElementsByName("select[]");
        var sall=document.getElementsByName("sall");

        function all()
        {
            for(var i=0;i<select.length;i++)
            {
                
                       select[i].checked="true";            
            }
        }
          function fall()
        {
            for(var i=0;i<select.length;i++)
            {
                     if(select[i].checked)
                     {
                     
                        select[i].checked="";
                    }
                     
                     else
                     {
                         select[i].checked="true";
                     }           
                
            }
        }
                        
         function nall()
        {
            for(var i=0;i<select.length;i++)
            {
                
                       select[i].checked="";      
                
            }
        }
                
        function mall(a){
            for(var i=0;i<select.length;i++)
            {
                select[i].checked=a.checked;
            }

        }
        </script>
     <a href="javascript:all()">全选</a>
     <a href="javascript:fall()">反选</a>
     <a href="javascript:nall()">全不选</a>
     <input type="checkbox"  onclick="mall(this)"/>全选
    </body>
</html>
if you don't try,you will never know!