How do you disable "Save as" function on images?

How do you disable "Save as" function on images?

    I want to the disable the save option in image and also disable copy the image  script will be given below:

 

 <style>
thumbnail.large,thumbnail.large .box-crop,thumbnail.large .box-contests,thumbnail.large .details,thumbnail.large .details .relative {width:100%;height:100%;}
thumbnail .details,thumbnail .details .relative {width:100%;height:100%;box-shadow:0;}
thumbnail .details .top .content {min-height:30px;}
thumbnail .details .top {display:block;font-size:16px;line-height:28px;text-align:center;}
thumbnail a:hover {text-decoration:none;}
thumbnail .details .top,thumbnail .details .bottom {width:100%;color:white;}
thumbnail .details .bottom {line-height:24px;}
thumbnail .closed .details .bottom.content {background:#D70200;text-align:center;line-height:26px;}
thumbnail .box-crop.crop-height img {width:100%;height:auto;margin-left:auto;}
thumbnail .details {position:absolute;top:0;left:0;}
</style>

<thumbnail class="large">
<img src="./images/pair.jpg" alt="Pair">
<a href="#"><div class="details"></div></a>
</thumbnail>

Download the Link:

https://www.box.com/shared/6rznbxxyt2fm956kgvao

The following file will be working fine.