如何网页上贴日历？

求解答，大家都不知道么？我又试了几次，可是贴上做好的日历格式都是散的有的部分还显示不出来。。。郁闷

下边是我的代码。使用html和php混编的，保存文件名为php文件calendar.php,单独运行时没问题的，可是贴不到自己的网站首页上去。
<?php
$now_year = date("Y");
$now_month = date("n");
$now_day = date("j");
$first_day = mktime( 0, 0, 0, $now_month, 1, $now_year );
$first_weekday = date( "w", $first_day );

?>

<?=$now_year?>年<?=$now_month?>月

<table border=1>
<tr bgcolor="#add8e6">
<th><font color=red>星期天</font></th>
<th><font color=black>星期一</font></th>
<th><font color=black>星期二</font></th>
<th><font color=black>星期三</font></th>
<th><font color=black>星期四</font></th>
<th><font color=black>星期五</font></th>
<th><font color=blue>星期六</font></th>
</tr>
<?php
echo "<tr>";  
$weekday = 0;
while( $weekday != $first_weekday ){
    echo "<td>&nbsp;</td>";
    $weekday++;
}

for( $day = 1; checkdate( $now_month, $day, $now_year ); $day++ ){

    if( $weekday > 6 ){
        $weekday = 0;
        echo "</tr>\n<tr>";
    }
   
    switch( $weekday ){
        case 0 :
            $color = "red";
            break;
        case 6 :
            $color = "blue";
            break;
        default :
            $color = "black";
    }

    if($day == $now_day){
                      echo "<td align=center bgcolor=\"#98fb98\"><font color=${color}>${day}</font></td>";
    }
     else {
             echo "<td align=center><font color=${color}>${day}</font></td>";
     }   
    $weekday++;
}

while( $weekday < 7 ){
    echo "<td>&nbsp;</td>";
    $weekday++;
}
echo "</tr>\n";  
?>
</table>