运行这段代码时存在一定问题，如图。
修改课题
$query=update $jiaoshi_table set subject='$subject1' where id='$id';
mysql_query(set names 'gb2312');
$result=mysql_query($query);
$query=update $jiaoshi_table set teacher='$teacher1' where id='$id';
mysql_query(set names 'gb2312');
$result=mysql_query($query);
$query=mysql_query(update $jiaoshi_table set zhicheng='$zhicheng1' where id='$id');
mysql_query(set names 'gb2312');
$result=mysql_query($query);
$query=mysql_query(update $jiaoshi_table set specialized='$specialized1' where id='$id');
mysql_query(set names 'gb2312');
$result=mysql_query($query);
$query=mysql_query(update $jiaoshi_table set code='$select' where id='$id');
mysql_query(set names 'gb2312');
$result=mysql_query($query);
$query=update $jiaoshi_table set beizhu='$introduction' where id='$id';
mysql_query(set names 'gb2312');
$result=mysql_query($query);
$query=select number as sn,surplus as ssn from $jiaoshi_table where id='$id';
mysql_query(set names 'gb2312');
$result=mysql_query($query);
$row=mysql_fetch_array($result);
if($number1 {
if($number1 {
echo人数不能少于现已选题人数，人数列修改失败！;
echo;
exit;
}
else
{
$query2=mysql_query(update $jiaoshi_table set number='$number1' where id='$id');
$query3=mysql_query(update $jiaoshi_table set surplus=surplus-($row[sn]-$number1) where id='$id');
mysql_query(set names 'gb2312');
$result1=mysql_query($query3);
}
}
else
{
$query4=mysql_query(update $jiaoshi_table set number='$number1' where id='$id');
$query5=mysql_query(update $jiaoshi_table set surplus=surplus+($number1-$row[sn]) where id='$id');
mysql_query(set names 'gb2312');
$result2=mysql_query($query5);
}
if($result==true)
{
echo
修改课题成功！;
echo ;
exit;
}
else
{
echo
修改出错，请返回重新修改
;
echo ;
exit;