title: declare php variable, isset? not isset?
body: <p>So here is my code:</p>
  
  <pre><code>&lt;?php 
      if (isset($_POST['submit'])){
          $tall1 = $_POST['tall1'];
  
          echo '&lt;script&gt;alert("hello!");&lt;/script&gt;'; 
  
      }
  ?&gt;
  &lt;div id="div1"&gt;
  &lt;form action="" method="POST"&gt;
      &lt;input class="form" id="tall1" name"tall1"&gt;
      &lt;select class="form" name="type"&gt;
          &lt;option&gt;+&lt;/option&gt;
          &lt;option&gt;-&lt;/option&gt;
          &lt;option&gt;*&lt;/option&gt;
          &lt;option&gt;/&lt;/option&gt;
      &lt;/select&gt;
      &lt;select class="form" name="color"&gt;
          &lt;option&gt;white&lt;/option&gt;
          &lt;option&gt;black&lt;/option&gt;
          &lt;option&gt;red&lt;/option&gt;
          &lt;option&gt;green&lt;/option&gt;
      &lt;/select&gt;
      &lt;input class="form" id="tall2" name"tall2"&gt;
      &lt;input type="submit" class="form"  name="submit" value="Submit"&gt;
  &lt;/form&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>This gives me this error: Notice: Undefined index: tall1 in C:\blabla\index.php on line 34
  , But i do get an echo...
  and if i do like this:</p>
  
  <pre><code>&lt;?php 
      if (isset($_POST['submit']) &amp;&amp; isset($_POST['tall1'])){
          $tall1 = $_POST['tall1'];
  
          echo '&lt;script&gt;alert("hello!");&lt;/script&gt;'; 
  
      }
  ?&gt;
  </code></pre>
  
  <p>It doesn't echo at all like it isn't working.</p>
  
  <p>What is the problem?</p>