关于一js的实现.
一页面: 
 在页面左侧有: "你好 "的文本和 "确定 "的按扭.我点击按扭后,在页面右侧显示 "你好 "的文本,同时还有text文本.当我再点左侧 "确定 "按扭的时候,右面的相关显示清空. 
------解决方案-------------------- <!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>  
  <meta http-equiv= "Content-Type " content= "text/html; charset=gb2312 " />  
  <title> 无标题文档 </title>    
  <style type= "text/css ">  
 #div1{ float:left} 
 #div2{width:200px; height:100px; line-height:100px; text-align:center; background:#eee; float:left} 
  </style>  
  </head>    
  <body>  
  <div id= "div1 ">  
  <input type= "text " id = "text1 "/>  
  <input type= "button " value= "click me " onclick= "modity(); " />  
  </div>    
  <div id= "div2 ">  </div>  
  </body>  
  </html>  
  <script type= "text/javascript ">    
 function modity() 
 { 
 	if(document.getElementById( "div2 ").innerHTML !=  " ") 
 	{ 
 		document.getElementById( "div2 ").innerHTML = " "; 
 	} 
 	else 
 	{ 
 		document.getElementById( "div2 ").innerHTML =  "你好!  " + document.getElementById( "text1 ").value; 
 	} 
 }     
  </script>    
 --- 
 这样的行不?
------解决方案-------------------- <!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>  
  <meta http-equiv= "Content-Type " content= "text/html; charset=gb2312 " />  
  <title> 无标题文档 </title>    
  <style type= "text/css ">  
 #div1{float:left} 
 #div2{width:200px; height:100px; line-height:100px; text-align:center; background:#eee; float:left} 
  </style>  
  </head>    
  <body>  
  <div id= "div1 ">  
  <input type= "text " id = "text1 " onKeyUp= "change(); "/>  
  <input type= "button " value= "click me " onclick= "modity(); " />  
  </div>    
  <div id= "div2 ">  </div>  
  </body>  
  </html>  
  <script type= "text/javascript ">    
 function modity() 
 {   
 		document.getElementById( "div2 ").innerHTML = " ";   
 }     
 function change() 
 { 
 	document.getElementById( "div2 ").innerHTML =  "你好!  " + document.getElementById( "text1 ").value; 
 }     
  </script>
------解决方案-------------------- <body>  
  <script language= "javascript ">  
 function doIt(obj){ 
     var oCon = document.getElementById( "conDiv "); 
     if(obj.clonedObj == null){ 
         var oNewCode = obj.cloneNode(true); 
         obj.clonedObj = oNewCode; 
         oCon.insertAdjacentElement( "beforeEnd ", oNewCode); 
     } else { 
         var oNewCode = obj.clonedObj; 
         oNewCode.removeNode(true); 
         obj.clonedObj = null; 
     } 
 }