Having problems getting Javascript to work on SharePoint 2010

Question

I was looking for help last week to get a simple javascript code made for SharePoint 2007 working for SharePoint 2010 and didn't really get a clear answer that i could use where i work unfortunately so i decided to try to just make my own. It's suppossed to be an Auction List and have a countdown in the "Time Left" field till the item expires, but i can't figure out what's wrong. I am very unfamiliar with javascript and sharepoint but i am an experienced programmer. Can anyone help with this? Here's the code below:

<script type="text/javascript">
var context = new SP.ClientContext.get_current();
var web = context.get_web();
var lists = web.get_lists();
var listId = SP.ListOperation.Selection.getSelectedList();
var list = lists.getById(listId);
var item = getItemByName("End Date");
var end = Date.parse(item.text())/1000;
var todayNow = new Date();
todayNow = Date.parse(today)/1000;
var result = (end-todayNow);
var item2 = getItemByName("Time Left");
item2.text(result);
</script>

The End Date is a field that will probably be hidden, but just used as a placeholder to find the difference from now till the item expires.

Thanks guys for any responses.

Answer 1

This may not be the root cause, but in your code snippet you did not include the </script> tag. Also, if you are using any other JavaScript libraries (I'm not sure if you are, I'm still a bit green) be sure to include them in the header.

You can close the code correctly in the following manner:

<script type="text/javascript"> 
    var context = new SP.ClientContext.get_current();
    var web = context.get_web();
    var lists = web.get_lists();
    var listId = SP.ListOperation.Selection.getSelectedList();
    var list = lists.getById(listId);
    var item = getItemByName("End Date");
    var end = Date.parse(item.text())/1000;
    var todayNow = new Date();
    todayNow = Date.parse(today)/1000;
    var result = (end-todayNow);
    var item2 = getItemByName("Time Left");
    item2.text(result);  
</script>

As a sidenote, to import any additional libraries simply lead your <script type="text/javascript"> with additional library calls. They look like this:

<script src="http://code.jquery.com/jquery-1.7.2.min.js" type="text/javascript"></script>

Simply place one of those in front of your script body for each library you want to call.