setInterval(clock,1000)
每隔1000ms，執(zhí)行一次clock函數(shù)

<script?type="text/javascript">
??var?int=setInterval(clock,?100)
??function?clock(){
????var?time=new?Date();
????document.getElementById("clock").value?=?time;
??}
</script>

相當(dāng)于以0.1s為周期執(zhí)行clock()函數(shù)