提交文件如下：

Tell Us About Your Baby!

What's your baby's name?
onfocus="java script:if(this.value=='enter the words' || ''){this.value=''}">

Is your baby a boy or girl?
Boy
Girl

What does your baby need?
Stroller
Toys
Food
A New Pair of Shoes

Rate your baby on a scale from 1 to 10.

1
2
3
4
5
6
7
8
9
10

What does your baby like to drink?

Juice
Milk
Water
Rum Punch

指向的文件如下：

$errors=array();

if(empty($name))
$errors[]="You didn't enter your baby's name.";
if(!isset($sex))
$errors[]="You didn't enter your baby's sex.";
if(!isset($rating))
$errors[]="Please rate your baby.";

if(is_array($drinks))
{
$ndrinks=count($drinks);
print $ndrinks;
var_dump($drinks);
for($i=0;$i<$ndrinks;$i++)
{
if($drinks[$i]="rum_punch")
{
$errors[]="You can't feed rum punch to a baby!";
}
}
}

$nerrors=count($errors);
if($nerrors>0)
{
print "

There were problems with your form. Please go back to the previous page and correct the following errors:

";
for($i=0;$i<$nerrors;$i++)
print "
• ".$errors[$i]."
\n";
print "

\n\n";
exit;
}

/*
$need_list="";
$drink_list="";
if(is_array($needs))
$need_list=join(", ",$needs);
if(is_array($drinks))
$drink_list=join(", ",$drinks);

$name = str_replace("\t"," ",$name);
$sex = str_replace("\t"," ",$sex);
$rating = str_replace("\t"," ",$rating);
$drink_list = str_replace("\t"," ",$drink_list);

$datafile="\\tmp\\baby_info_datafile.txt";
$fp=fopen($datafile,"a");
if($fp==false)
die("Can't open data file \"$datafile\".\n");
fwrite($fp,$name."\t".$sex."\t".$rating."\t".$need_list."\t".$drink_list."\n");
fclose($fp);
*/
?>

Thanks for taking our survey!

当没有选择多项选单的任何无素时~~~弹出如下信息：
Notice: Undefined variable: drinks in C:\Program Files\Apache Group\Apache2\htdocs\baby-survey-1-handler.php on line 11

当任意选择一个或多个无素时~~~用来记录错误的数组$errors都会所被选择的无素记录为错误，即出现：
You can't feed rum punch to a baby!

可我的代码却时：
if(is_array($drinks))
{
$ndrinks=count($drinks);
print $ndrinks;
var_dump($drinks);
for($i=0;$i<$ndrinks;$i++)
{
if($drinks[$i]="rum_punch")
{
$errors[]="You can't feed rum punch to a baby!";
}
}
}


我实在看不出那里出错了~~~
请大家帮忙