title: How do I disable a HTML tag
body: <p>I have numerous html input tags, which takes the user input and post it to a variable, code :</p>
  
  <pre><code>&lt;form method = "post" action=""select.php&gt; 
      &lt;input id="nol" style="width: 280px;" type="text" name="searchdisease" placeholder="type diagnosis one"&gt;
      &lt;input id="nol" style="width: 280px;" type="text" name="searchdisease1" placeholder="type diagnosis two"&gt;
      &lt;input id="nol" style="width: 280px;" type="text" name="searchdisease2" placeholder="type diagnosis three"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>then this variable i append it to SQL  query to retrieve data LIKE user input code: </p>
  
  <pre><code>$search_disease = $_POST['searchdisease'];
  $search_disease1 = $_POST['searchdisease1'];
  $search_disease2 = $_POST['searchdisease2'];
  
  $query="SELECT diagnosis FROM medications WHERE diagnosis LIKE '%$search_disease%'";
  $result= $con-&gt;query($query);
  $query1="SELECT diagnosis FROM medications WHERE diagnosis LIKE '%$search_disease1%'";
  $result1= $con-&gt;query($query1);
  $query2="SELECT diagnosis FROM medications WHERE diagnosis LIKE '%$search_disease2%'";
  $result2= $con-&gt;query($query2);
  </code></pre>
  
  <p>, then echo the results to a select tag.
  code:</p>
  
  <pre><code>&lt;select id="disease" style="width: 40%;" name="tdisease"&gt;
     &lt;option value=""&gt;Select Disease&lt;/option&gt;
     &lt;?php
         while ($row=$result-&gt;fetch_array(MYSQLI_ASSOC)) { 
     ?&gt;
         &lt;option value="&lt;?php echo $row['ICD10']?&gt;"&gt;&lt;?php echo $row['diagnosis'];?&gt; &lt;/option&gt; 
     &lt;?php } ?&gt; 
  &lt;/select&gt;
  &lt;select id="disease" style="width: 40%;" name="tdisease1"&gt;
     &lt;option value=""&gt;Select Disease&lt;/option&gt;
     &lt;?php
         while ($row=$result1-&gt;fetch_array(MYSQLI_ASSOC)) { 
     ?&gt;
         &lt;option value="&lt;?php echo $row['ICD10']?&gt;"&gt;&lt;?php echo $row['diagnosis'];?&gt; &lt;/option&gt; 
    &lt;?php } ?&gt; 
  &lt;/select&gt;
  &lt;select id="disease" style="width: 40%;" name="tdisease2"&gt;
       &lt;option value=""&gt;Select Disease&lt;/option&gt;
       &lt;?php
           while ($row=$result2-&gt;fetch_array(MYSQLI_ASSOC)) { 
       ?&gt;
              &lt;option value="&lt;?php echo $row['ICD10']?&gt;"&gt;&lt;?php echo $row['diagnosis'];?&gt; &lt;/option&gt; 
       &lt;?php } ?&gt; 
  &lt;/select&gt;
  </code></pre>
  
  <p>So i want to know how can i use JavaScript to disable or hide the select tags when the user input is empty? </p>