php-PHP提交文本带有 and 数字 服务器提示出错

服务器php

<code> <form action="test.php" method="post">
<input class="inputtext" name="str1" type="text" value="test and 1 test"><input type="submit" value="提交">
</form>
<?php $a=$_POST['str1'];   echo $a;?></code>

例如输入test and 1 test这串提交的话会出错, test and s test 这样正常
带有and 加数字就会报错.
POST 和GET都一样
出错信息

<code> ForbiddenYou don't have permission to access /test.php on this server.Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. </code>