javascript输出html标签问题(100分求)
<HTML>  
  <HEAD>  
  <TITLE>    New   Document    </TITLE>  
  </HEAD>    
  <BODY>  
  <FORM   METHOD=POST   ACTION= "Noname3.html ">  
  </FORM>  
  <INPUT   TYPE= "text "   NAME= "AA "   id= "AA "   >  
  <INPUT   TYPE= "submit "   onclick   = "Test(AA.value) ">  
  <HR>    
  <!--   想在 <HR>    后面再画a-1的    <HR>    .   这样似乎不可以呀!-->  
  <SCRIPT   LANGUAGE= "JavaScript ">  
  <!-- 
 	function   Test(a) 
 	{ 
 		var   tmp   =   a-1; 
 		if   (tmp   >    0) 
 		{ 
 			while   (tmp   >    0) 
 			{ 
 				document.write( " <hr>  "); 
 				tmp--; 
 			} 
 		} 
 	} 
 //-->  
  </SCRIPT>  
  </BODY>  
  </HTML>         
 文本输入   3   ,点提交! 
 想实现      在本页面后面再画   3-1   个横线 <hr> 了      
 现在的程序画了!却把以前的文本和横线覆盖了      
 怎么可以亚!      
------解决方案-------------------- <HTML>  
  <HEAD>  
  <TITLE>  New Document  </TITLE>  
  <!-- 想在 <HR>  后面再画a-1的  <HR>  . 这样似乎不可以呀!-->  
  <SCRIPT LANGUAGE= "JavaScript ">  
  <!-- 
 	function Test(a) 
 	{ 
 		var tmp = a-1; 
 		if (tmp >  0) 
 		{ 
 			while (tmp >  0) 
 			{ 
 				//document.write( " <hr>  "); 
 				var o=document.getElementById( "a "); 
 				alert(o); 
 				var t=document.createElement( "hr "); 
 				o.appendChild(t); 
 				tmp--; 
 			} 
 		} 
 	} 
 //-->  
  </SCRIPT>  
  </HEAD>    
  <BODY>    
  <INPUT TYPE= "text " NAME= "AA " id= "AA " >  
  <INPUT TYPE= "button " onclick = "Test(AA.value) " value= "add ">  
  <HR id= "hr1 ">  
  <div id= "a ">      
  </div>  
  </BODY>  
  </HTML>
------解决方案--------------------可以在div里画: 
  <HTML>  
  <HEAD>  
  <TITLE>  New Document  </TITLE>  
  </HEAD>    
  <BODY>  
  <FORM METHOD=POST ACTION= "Noname3.html ">  
  </FORM>  
  <INPUT TYPE= "text " NAME= "AA " id= "AA " >  
  <INPUT TYPE= "submit " onclick = "Test(AA.value) ">  
  <HR>  
  <div id= "draw_hr ">  </div>  
  <!-- 想在 <HR>  后面再画a-1的  <HR>  . 这样似乎不可以呀!-->  
  <SCRIPT LANGUAGE= "JavaScript ">  
  <!-- 
 function Test(a) 
 { 
 var tmp_html= " "; 
 for (var tmp=1; tmp <a; tmp++) 
 { 
 tmp_html+= " <hr>  "; 
 } 
 draw_hr.innerHTML=tmp_html; 
 } 
 //-->  
  </SCRIPT>  
  </BODY>  
  </HTML>