Code
<script language="JavaScript">
<!--
var flag=0;
function myclock()
{
if(flag==1)
{
ndata= new Date();
hours= ndata.getHours();
minutes= ndata.getMinutes();
seconds= ndata.getSeconds();
datastr=""+ ((hours < 10) ? "0" : " ") + hours;
datastr+= ((minutes < 10) ? ":0" : ":") + minutes;
datastr+= ((seconds < 10) ? ":0" : ":") + seconds;
window.document.clockexam.clock.value = datastr;
}
setTimeout("myclock();",1000);
}
function startc()
{
flag=1;
}
function stopc()
{
flag=0;
}
-->
</script>
</head>
<body onLoad="myclock()">
<form name="clockexam">
<input type="text" name="clock" size="8">
<input type=button value="Включить" onClick="startc();">
<input type=button value="Стоп" onClick="stopc();">