超简单的定时器问题?
<Script>    
 function   show()   {               
             document.write(new   Date().getSeconds()); 
                setTimeout( "hide() ",500); 
 }   
 function   hide()   {                  
             setTimeout( "show() ",500); 
 }   
  </Script>    
  <Body   onload= "show() ">  
  </Body>    
 怎么没用呢         郁闷~说网页中有错误`         --一新手    
------解决方案--------------------document.write不能用在onload事件中及其以后. 
------解决方案-------------------- <!DOCTYPE HTML PUBLIC  "-//W3C//DTD HTML 4.0 Transitional//EN ">  
  <html>  
  <head>  
  <title>  New Document  </title>  
  <meta name= "Generator " content= "EditPlus ">  
  <meta name= "Author " content= " ">  
  <meta name= "Keywords " content= " ">  
  <meta name= "Description " content= " ">  
  </head>    
  <body>  
  <Script>  
 	div = document.createElement( "div "); 
 	div.id=  "div "; 
 	document.body.appendChild(div);   
 function show() {       
    // document.write(new Date().getSeconds());  	 
 	div.innerHTML = new Date().getSeconds(); 
      setTimeout( "hide() ",500); 
 }   
 function hide() {        
     setTimeout( "show() ",500); 
 }   
  </Script>    
  <Body onload= "show() ">  
  <input type= "button " onclick= "alert(document.body.innerHTML); ">  
  </Body>  
  </body>  
  </html>