JavaScript实现HTML代码实时预览功能

<HTML>
<HEAD>
<TITLE>直接页面显示器</TITLE>
<STYLE type="text/css">
BODY{MARGIN-TOP: 0px;FONT-SIZE: 9pt;MARGIN-LEFT: 4px;MARGIN-RIGHT: 0px;FONT-FAMILY: "微软雅黑"}
A{FONT-WEIGHT: 400;FONT-SIZE: 13px;COLOR: black;TEXT-DECORATION: none}
A: hover{FONT-WEIGHT: 400;FONT-SIZE: 13px;COLOR: red;TEXT-DECORATION: underline}
A: active{CURSOR: hand;COLOR: #ff0033}
.STYLE1{color: #0000FF;font-size: 40px;}
.STYLE2{font-weight: bold;font-size: 30px;}
</STYLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
</HEAD>
<BODY>
<CENTER>
 <span class="STYLE1"><FONT face=隶书>直接页面显示器</FONT></span>
</CENTER><BR>
<CENTER>
<TABLE style="BORDER-COLLAPSE: collapse" borderColor=#111111 cellSpacing=0 
cellPadding=0 border=0 borderlight="green">
 <TBODY>
 <TR>
  <TD align=middle><span class="STYLE2"><FONT color=red>请在下面窗口中输入HTML代码</FONT></span></TD>
 </TR>
 <TR>
  <TD align=middle>
<SCRIPT language=JavaScript>
function trestart(){
  if (script) {
  clear = confirm("确定要清除吗？",'');
  if(clear) {
  document.script.reset();
  document.script.value = "";
 }
 }
} 
function test(){
 {
 temp = document.script.tester.value;
 testwin= open("", "testwin","status=no,menubar=yes,toolbar=no");
 testwin.document.open();
 testwin.document.write(temp);
 testwin.document.close();
 }
}
function about(){
 alert("HTML代码直接显示出页面来")
}
function help(){ 
 OpenWindow=window.open("", "newwin","height=220,width=470,toolbar=no,scrollbars="+scroll+",menubar=no");
 OpenWindow.document.write("<body bgcolor='white' text='black' alink='blue'vlink='blue' link='blue'><TITLE>帮助信息</TITLE>")
 OpenWindow.document.write("<center>你只要把你想显示的代码放到上页的输入框中，你自己也可以写代码，按显示键就能显示你的页面内容</center><br>")
 OpenWindow.document.write("<center><a href='javascript:close()'>关闭本窗口</a></Center>")
 OpenWindow.document.close()
 self.name="main"
}
</SCRIPT>
   <FORM name=script><TEXTAREA name=tester rows=8 wrap=off cols=50></TEXTAREA> <BR><INPUT onclick=test() type=button value=显示>&nbsp;&nbsp; <INPUT onclick=trestart() type=button value=清除>&nbsp;&nbsp; <INPUT onclick=about() type=button value=关于>&nbsp;&nbsp; <INPUT onclick=help() type=button value=帮助> 
</FORM></TD></TR></TBODY></TABLE></CENTER>
<CENTER>
<DIV align=center>
<CENTER>
<TABLE id=AutoNumber1 style="BORDER-COLLAPSE: collapse" borderColor=#111111 
cellSpacing=0 cellPadding=0 width=360 border=0>
 <TBODY>
 <TR>
  <TD>
   <P align=left><SPAN style="FONT-SIZE: 9pt">将下面代码复制到输入框试试<BR><FONT 
   color=#ff0033><BR>&lt;html&gt;<BR>&lt;head&gt;<BR>&lt;title&gt;你好&lt;/title&gt;<BR>&lt;/head&gt;<BR><BR>&lt;body&gt;<BR>
      你好，欢迎光临本站网页特效栏目！<BR>
   &lt;/body&gt;<BR><BR>&lt;/html&gt;</FONT></SPAN></P></TD></TR></TBODY></TABLE></CENTER></DIV>
</BODY>
</HTML>