<script language="javascript">
function checktext()
{
if((form1.yeartext.value == "") && (form1.monthtext.value == "") && (form1.datetext.value == ""))
{
alert("请输入相关信息!");
form1.yeartext.focus();return;
}
if((form1.yeartext.value.length !=4 ) && (form1.monthtext.value.length !=1 ) && (form1.datetext.value.length !=1 ))
{
alert("输入错误，只能输入4位数！");
form1.yeartext.focus();return;
}
}
function mod(x, x_div)
{
for (var i=x; i>=x_div; i -= x_div);
return i;
}
function getday()
{
var currentyear = parseInt(form1.yeartext.value,10);
var currentmonth = parseInt(form1.monthtext.value,10);
var currentday = parseInt(form1.datetext.value,10);
var sig_val;
var begindate = new Array(0,3,3,6,1,4,6,2,5,0,3,5);
var rundate = new Array(-1,2,2,5,0,3,5,1,4,-1,2,4);
var Pmonth = new Array(29,31,28,31,30,31,30,31,31,30,31,30,31)
var montharray = new Array("星期日","星期一","星期二","星期三","星期四","星期五","星期六");
sig_val =begindate[currentmonth - 1];
var val1 = mod((currentyear + parseInt(currentyear/4) + currentday + sig_val)-2,7);
var M=parseInt(document.all.monthtext.value);
var D=parseInt(document.all.datetext.value);
if ((currentyear%4==0 && currentyear%100!=0)||(currentyear%400==0))
{
if ((M<13)&&(M>0)){
if ((M==2)&&(D>Pmonth[0])){alert('输入错误');document.all.resulttext.value='';}
else{
if ((D>Pmonth[M])&&(M!=2)){alert('输入错误');document.all.resulttext.value='';}
else{
sig_val =rundate[currentmonth - 1];
val1 = mod((currentyear + parseInt(currentyear/4) + currentday + sig_val)-2,7);
if (M>2){val1+=1;}
form1.resulttext.value =montharray[val1];
}
}
}else{alert('输入错误');document.all.resulttext.value='';}
}
else
{
if ((M<13)&&(M>0)){
if (D>Pmonth[M]){alert('输入错误');document.all.resulttext.value='';}
else{form1.resulttext.value =montharray[val1];}
}else{alert('输入错误');document.all.resulttext.value='';}
}
}
</script>

<center>
<form name="form1" method="post" action="">
<table width="308" border="1" cellpadding="3" cellspacing="1" bordercolor="#33CCFF" bgcolor="#CCFFFF">
<tr bgcolor="#FFFFFF">
<td align="center" class="style5">输入年：</td>
<td width="170"><input name="yeartext" type="text" id="yeartext" value="2016"></td>
</tr>
<tr bgcolor="#FFFFFF">
<td align="center" class="style5">输入月：</td>
<td><input name="monthtext" type="text" value="2"></td>
</tr>
<tr bgcolor="#FFFFFF">
<td align="center" class="style5">输入日：</td>
<td><input name="datetext" type="text" value="2"></td>
</tr>
<tr bgcolor="#FFFFFF">
<td align="center"><span class="style5">星  期：</span></td>
<td><input name="resulttext" type="text" id="resulttext"></td>
</tr>
<tr align="center" bgcolor="#FFFFFF">
<td colspan="2">
<div align="right">
<input name="enter" type="button" value="计算" onClick="checktext();getday();">
</div>
</td>
</tr>
</table>
</form>
</center>