JavaScript get child element

Question

Why this does not work in firefox i try to select the category and then make subcategory visible.

<script type="text/javascript">     function show_sub(cat) {       var cat = document.getElementById("cat");       var sub = cat.getElementsByName("sub");       sub[0].style.display='inline';  }  </script> 

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<ul>     <li id="cat" onclick="show_sub(this)">         Top 1         <ul style="display:none" name="sub">             <li>Sub 1</li>             <li>Sub 2</li>             <li>Sub 3</li>         </ul>     </li>     <li>Top 2</li>     <li>Top 3</li>     <li>Top 4</li> </ul> 

EDIT Answer is:

<script type="text/javascript">    function show_sub(cat) {       cat.getElementsByTagName("ul")[0].style.display = (cat.getElementsByTagName("ul")[0].style.display == "none") ? "inline" : "none";    } </script> 

Answer 1

ULs don't have a name attribute, but you can reference the ul by tag name.

Try replacing line 3 in your script with this:

var sub = cat.getElementsByTagName("UL");