JS to change img tag

Question

I have a bunch of java-script in one page. Working (this time :) )

When I add the following simple code everything stops working, is there a small type or something I am missing?

if(document.getElementById('checkBottom').checked)
{
     document.getElementById('preview_hl_front').src = "./assets/images/bottom---highligt-front.png";
{
else
{
     document.getElementById('preview_hl_front').src = "./assets/images/highligt-front.png";
}

Other components:

<input type="checkbox" name="bottom" id="checkBottom" value="yes" data-preview="preview_bottom" onclick="validate()">

    <div class="panel panel-default">
        <div id="preview">
        <img src="./assets/images/highligt-front.png" id="preview_hl_front" />
        </div>
    </div>

Answer 1

You have a typo. you closed the if block with { instead of }
Change this:

if(document.getElementById('checkBottom').checked)
{
     document.getElementById('preview_hl_front').src = "./assets/images/bottom---highligt-front.png";
{

To this:

if(document.getElementById('checkBottom').checked)
{
     document.getElementById('preview_hl_front').src = "./assets/images/bottom---highligt-front.png";
}