javascript - How do I make the dropdown arrow appear. Just like in the second image

Question

[the image from my own website

I want the first image to look like this with a drop down arrow

I have this so far

<li class="zs-dropdown">
  <a href="" aria-haspopup="true" aria-expanded="true" id="data_files/zs-dropdown-arrow-default.gif">Products<span class="data_files/zs-dropdown-arrow-default.gif"> <aria-hidden="true"></span><span class="data_files/zs-dropdown-arrow-default.gif"> <aria-hidden="true"></span></a>
  <ul class="zs-dropdown-content" aria-labelledby="data_files/zs-dropdown-arrow-default.gif">

Answer 1

等待大神答复