设计一个答题计时器。在线等

[jspgirl]

<script language="javascript">
var outtime=30;
function leavePage()
{
if(0==outtime)
{
location.href="";
}
else
{
outtime -= 1;
document.all.countdown.innerText = outtime + " ";

setTimeout("leavePage()", 1000);
}
}
setTimeout("leavePage()", 1000);
</script>

已经设计了一个答题计时器，请问怎样修改能够在某个时候让它自动停止计时，而且保持原来时间不变！谢谢。

[jspgirl]

帮帮忙阿,如果分数不够可以再加啊!多少都可以!

[deerchao]

var ps;

function pause()
{
ps=setInterval("outtime++",1000);
}

function continue()
{
clearInterval(ps);
}

[无爱大叔]

<script language="javascript">
var outtime=30;
function leavePage()
{
if(0==outtime)
{
location.href="";
}
else
{
outtime -= 1;
document.all.countdown.innerText = outtime + " ";
}
}

function go()
{
t = setInterval("leavePage()", 1000);
}

function stop_exec()
{
clearInterval(t);
}

go();
</script>
<span id=countdown></span>
<br>
<input type=button onclick="stop_exec();" value="stop timer">
<input type=button onclick="go();" value="start timer">