PHP Outputting XML file

[chuy08@gmail.com]

I am trying to create an XML file using a PHP script. The XML File
looks something like this:

<?xml version="1.0" encoding="ISO-8859-1"?>
<ConsumerDirect XML>
<UserParams id="1" BrokerID="1"/>
<LoanParams>
<FirstLeinAmt>5 00000</FirstLeinAmt>
<ChooseProductT ypeID>1</ChooseProductTy peID>
</LoanParams>
</ConsumerDirectX ML>

The part that I don't understand is the following. I have a series of
checkboxes with each box having a different value. If a user were to
select 3 checkboxes I need to iterate through the array and write to
the ChooseProductTy peID field in the XML file as such,
<ChooseProductT ypeID>1,5,7</ChooseProductTy peID>. I have been able to
print out the array variable $num using the following foreach loop:

foreach ($total as $num) {
print("$num,"); }

How would I get this string into the designated XML tag?

Currently I am able to write to this XML file using textboxes and the
following code for different XML tags in same file. How would I modify
what I am currently using for textboxes to use for the checkboxes while
utilitzing the foreach loop. Below is the method by which I am
writting to my XML file:

if ($node_name == "FirstLeinA mt") {
if ($value == $firstlein) {
// Do nothing
} else {
$fl_textnode = $child_obj->firstChild;
$new_firstlein = $doc->createTextNode ($firstlein);
$child_obj->replaceChild($ new_firstlein, $fl_textnode);
}
}
foreach ($total as $num) {
if ($node_name == "ChoosedProduct TypeID") {
if ($value == $num) {
// Do nothing
} else {
$pt_textnode = $child_obj->firstChild;
$new_num = $doc->createTextNode ("$num,");
$child_obj->replaceChild(" $new_num", "$pt_textnode") ;
}}
....


Any help appreciated.