few quick basic html questions

[Caution]

Doing a project right now, can't figure out how to do a couple things.

1) One of my functions has a parameter (an image) that doesn't exist. The textbook suggests to use object detection "to determine whether a div element with the value of the photo parameter exists". I've looked at the section talking about object detection for a while and I still can't figure out how to do this.

.. That's the main problem, I'll probably figure out these last two before I get a response, but I'll ask anyway.

2) what function reloads the browser window

3) how can I get an image to run a function using href, without it linking to another page

[AricC]

<!-- BEGIN SCRIPT -->
 
 <noscript>
<meta http-equiv="refresh" content="15; url=target.html">
</noscript>
 
<script>
<!--
  var version = parseInt(navigator.appVersion)
  // replace is supported
 
  if (version>=4 || window.location.replace)
  setTimeout("window.location.replace('target.html')",15000);
  else
    window.location.href = "target.html"
// -->
</script>
 
 <!-- END SCRIPT -->

Not sure what you mean by this post the code your trying to get working.

3) how can I get an image to run a function using href, without it linking to another page

[Caution]

I need to make an image follow a path around another image after it's clicked by running a function that I've already created, I just can't figure out the syntax to start it

[Caution]

Any suggestion for the first part?

I have a function called describeIt() that has two attributes: text and photo. Some of the times I use this function, I don't need a photo, so the text says to use object detection to find out if photo isn't blank so I can run a function to show the photo