亲，帮忙给看看这个类哪里出有关问题了？出不来表格啊 _PHP

亲，帮忙给看看这个类哪里出问题了？出不来表格啊？？？
<?php
class Create{
  var $i;
  var $j;
  function table(){
  echo "<table>";
    if($a=1;$a<=$i;$a++){
  echo "<tr>";
  if($b=1;$b<=$j;$b++){
     echo "<td>$nbsp;</td>";
  }
echo "</tr>";
}
echo "</table>";
  }
}
$table=new Create();
$table->i=3;
$table->j=4;
$table->table();
?>

------解决方案--------------------

本帖最后由 xuzuning 于 2013-02-01 10:56:02 编辑

class Create{
  var $i;
  var $j;
  function table(){
  echo "<table>";
    for($a=1;$a<=$this->i;$a++){
  echo "<tr>";
  for($b=1;$b<=$this->j;$b++){
     echo "<td> </td>";
  }
echo "</tr>";
}
echo "</table>";
  }
}
$table=new Create();
$table->i=3;
$table->j=4;
$table->table();