求一简单问题~如何迭代HTML上所有的控件
页面上有很textbox   button 
 如何迭代这些控件以及判断这些控件是属于button   还是textbox?   
  <form   name= "form1 ">  
  <input   type= "button "   name= "button1 "   value= "button1 ">  
  <input   type= "button "   name= "button2 "   value= "button2 ">  
  <input   type= "button "   name= "button3 "   value= "button3 ">  
  <input   type= "text "   name= "text1 ">  
  <input   type= "text "   name= "text2 ">  
  <input   type= "text "   name= "text3 ">  
  </form>
------解决方案--------------------function getElements() 
 { 
 	var f = document.getElementsByName( 'form1 '); 
 	for (var i = 0, l = f.length; i  < l ; i++ ) 
 	{ 
 		for (var j = 0, k = f[i].all.length; j  < k ;j++ ) 
 		{ 
 			alert(f[i].all[j].type); 
 		} 
 	} 
 }
------解决方案-------------------- <html>  
  <head>  
  <title>  </title>  
  <script language= "JavaScript ">    
 window.onload = function() 
 { 
     GetNodes(document.body); 
 } 
 function GetNodes(parent) 
 { 
     var children = parent.children; 
     for (var i = 0; i  < children.length; i++) 
     { 
         alert( "Tag Name:  " + children[i].tagName + 
             (children[i].type == undefined ?  " " :  "\nType:  " + children[i].type) + 
             (children[i].value == undefined ?  " " :  "\nValue:  " + children[i].value)); 
         GetNodes(children[i]); 
     } 
 }   
  </script>  
  </head>  
  <body>  
  <form name= "form1 ">  
  <input type= "button " name= "button1 " value= "button1 ">  
  <input type= "button " name= "button2 " value= "button2 ">  
  <input type= "button " name= "button3 " value= "button3 ">  
  <input type= "text " name= "text1 ">  
  <input type= "text " name= "text2 ">  
  <input type= "text " name= "text3 ">  
  </form>  
  <br>  
  <p>  </p>  
  <button> 按钮 </button>  
  <ul>  <li> rrrewrtqt </li>  </ul>  
  </body>  
  </html>