Solution
Okay so below i have documented what i had to change to get this to work for me. Open to critasism
First as descriped above i added the Line of code into the newticket.inc.php so the table row source now looks like this
<tr>
<td align="left"><b>Ticket Source:</b></td>
<td>
<select name="source">
<option value="" selected >Select Source</option>
<option value="phone" <?=($info=='phone')?'selected':''?>>Phone</option>
<option value="email" <?=($info=='email')?'selected':''?>>Email</option>
<option value="counter" <?=($info=='counter')?'selected':''?>>Counter</option>
<option value="phone" <?=($info=='other')?'selected':''?>>Other</option>
</select>
<font class="error"><b>*</b> <?=$errors?></font>
</td>
</tr>
Then I added "Counter" to the ticket_table under source so the Type is now enum("Web", "Phone", "Email", "Counter")
And finally the bit i was having trouble with. validating the new source. under scp/tickets.php there is the following statment:
if($_POST && !in_array($_POST,array('email','phone','other')))
$errors='Invalid source';
and all i did was change it to the following:
if($_POST && !in_array($_POST,array('email','phone','counter','other')))
$errors='Invalid source';
All pretty basic stuff but as i said i'm new to this, hope this helps anyone else needing to do the same kinda thing.