灰色定时按钮

<table cellpadding="3" cellspacing="1" align=center class="tableborder1"><form id="aform" name="aform" method=post><input type="hidden" id="action" name="action" value="apply"><tr><td class="tablebody1"><div style=" margin: 10px; line-height: 1.5"><span lang="zh-cn">注册信息，，，，，，，，，，，，，，，，，，xindaima.cn</span><BR></div></td></tr><tr><td align=center class=tablebody2><input type=submit id="regsubmit" name="regsubmit" value=" 我同意 " style="width:100">　　<button onclick=history.go(-1) Style='Width=100'>不 同 意</button></td></tr></form></table><script language="javascript">
var secs = 10;
var wait = secs * 1000;
var agreetext=" 我同意 ";
document.aform.regsubmit.value = agreetext+"(" + secs + ") ";
document.aform.regsubmit.disabled = true;
for(i = 1; i <= secs; i++) {
window.setTimeout("update(" + i + ")", i * 1000);
}
window.setTimeout("timer()", wait);
function update(num, value) {
if(num == (wait/1000)) {
document.aform.regsubmit.value = agreetext;
} else {
printnr = (wait / 1000)-num;
document.aform.regsubmit.value = agreetext+"(" + printnr + ") ";
}
}
function timer() {
document.aform.regsubmit.disabled = false;
document.aform.regsubmit.value = agreetext;
}
</script>