<body>
<script language="javascript">
function panduan(){
var a1=document.form1.day.value
if(a1>0&&a1<=7){
if(a1==7){
a1="天"
}
alert("星期"+a1)
}
else{
alert("输入错误!")
}
}
</script>
<form id="form1" name="form1" method="post" action="">
<label>
<input type="text" name="day" />
</label>
<label>
<input type="button" name="Submit" value="按钮" onclick="panduan()" />
</label>
</form>
</body>
<form id="form1" name="form1" method="post" action="">
写这句是什么意思呢