51help TIY
码：
<html> <head> <script type="text/javascript"> var c=0 var t function timedCount() { document.getElementById('txt').value=c c=c+1 t=setTimeout("timedCount()",1000) } function stopCount() { c=0; setTimeout("document.getElementById('txt').value=0",0); clearTimeout(t); } </script> </head> <body> <form> <input type="button" value="" onClick="timedCount()"> <input type="text" id="txt"> <input type="button" value="" onClick="stopCount()"> </form> <p>时，从 0 置为 0。</p> </body> </html>
查看结果: