How to make it only visible not hide the contents?

I want the contents to be visible once clicked but this script hide it on second click too..

Code:

---

<!--
    function toggle_visibility(id) {
      var e = document.getElementById(id);
      if(e.style.display == 'block')
          e.style.display = 'none';
      else
          e.style.display = 'block';
    }
//-->

---

Code:

---

<li><a href="#" onclick="toggle_visibility('Websites'); ">Websites</a></li>

---

Code:

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<div id="Websites">
       
<-----------  CONTENTS INSIDE-------------->
       
        </div>

---

So i want to make it only show when i click on the nav menu known as "Websites".But it hides on 2nd click.
Please help me..


Thank you ;)

You want to let it remain visible once it is visible?

Code:

---

<!--
    function toggle_visibility(id) {
      var e = document.getElementById(id);
      e.style.display = 'block';
    }
//-->

---