注意:未定义的索引:第6行的C:\ xampp \ htdocs \ mytestform \ addentry.php中的op

祝大家有美好的一天

我是php编程的新手，但是我被卡住了，有人可以帮忙吗.

这是我的代码

Good day to you all

i''m new to php programing and i''m stuck could someone help please.

Here is my code

<pre lang="xml"><?php<br />
<br />
isset($_POST[''op'']) && $_POST[''op''] != "add";<br />
<br />
if ($_POST[''op''] != "add" )<br />
     {<br />
      //havent seen form, so see it<br />
     $display_block = "<h1>Add an Entry</h1><br />
       <form method = \"post\" action =\"$_SERVER[PHP_SELF]\"></pre><br />

下一部分是我的表格，我以
结尾

the next part is my form and i end the form with

<pre lang="xml"><p><input type = \"submit\"  name=\"submit\" value=\"Add Entry\"></p><br />
<br />
       </form>";<br />
      }<br />
     else if ($_POST[op] == "add" ) //check required fields<br />
     {<br />
      if (($_POST[Venue_name] == "") || ($_POST[Venue_date] == ""))<br />
      {header("Location:addentry.php");<br />
       exit;<br />
     }</pre><br />

谢谢