PHP生成月历代码

        for($a=1;$a<=5;$a++){
            print("<tr align="left" valign="top" style="font-family: Verdana; font-size:x-small">");
            $diffDays = $firstDay-$lastDay;
            if($firstDay>$lastDay && $currentDays ==1 && ($diffDays<>1)){
                for($x=$lastDay;$x>=0;$x--){
                    $printDays = $days-$x;
                    print("<td>$printDays</td>");
                }
                for($z=1;$z<$firstDay-$lastDay;$z++){
                    print("<td> </td>");
                }
                for($y=$firstDay;$y<7;$y++){
                    print("<td>$currentDays</td>");
                    $currentDays++;
                }
            } elseif($firstDay!=0 && $currentDays==1){
                for($z=1;$z<=$firstDay;$z++){
                    print("<td> </td>");
                }
                for($y=$firstDay;$y<7;$y++){
                    print("<td>$currentDays</td>");
                    $currentDays++;
                }