如何用類的對象的方法控制輸入文本框的大小
<form>  
 輸入關鍵字: 
  <input   type= "text "   id= "key "   name= "key "   size= "10 ">  
  <br>  
 輸入文章: 
  <input   type= "text "   id= "text "   name= "word "   size= "10 ">  
  <script   src= "se.js ">  
  </script>  
  </form>    
 以下是se.js 
 function   obj()   { 
 	this.key=document.forms[0].key.value; 
 	this.word=document.forms[0].word.value; 
 	function   changeSize() 
 	{ 
 		document.forms[0].key.size=document.forms[0].key.value.length; 
 		document.forms[0].word.size=document.forms[0].key.word.length; 
 	} 
 } 
 e=new   obj(); 
 e.changeSize();   
 運行時說腳本有錯誤,哪裡錯了? 
 還有我想text框裡的文字發生變化時就調用changeSize方法,使text框的長度和裡面文字大小一樣,是不是控件的onChange事件呢?如何修改? 
 js裡對表單元素的引用如何簡單點?
------解决方案-------------------- <html>  
  <head>  
      <title> 变长文本框 </title>  
  </head>  
  <body>  
  <input type= "text " name= " " id= "text1 "/>  
  <script type= "text/javascript ">  
     var Env = function() { 
     }; 
     Env.attachEvent = function(elem, eventName, callback) { 
         if (elem.addEventListener) { // Non-IE browsers 
             elem.addEventListener(eventName, callback, false);   
         } else if (elem.attachEvent) { // IE 6+ 
             elem.attachEvent( 'on ' + eventName, callback);   
         } else { // Older browsers 
             var currentEventHandler = elem[ 'on ' + eventName]; 
             if (currentEventHandler == null) { 
                 elem[ 'on ' + eventName] = callback; 
             } else { 
                 elem[ 'on ' + eventName] = function(e) { 
                     currentEventHandler(e); 
                     callback(e); 
                 } 
             } 
         } 
     }   
     var ResizableTextbox = function(id) { 
         var text = document.getElementById(id); 
         Env.attachEvent(text,  "keypress ", function() { 
             text.size = text.value.length + 1; 
         }) 
     }   
     ResizableTextbox( "text1 "); 
  </script>  
  </body>  
  </html>    
 不过中文字就要多一点判断了