I don't know a damn thing about XML but..
Try encasing the variable in single ' quotes instead of double " quotes.
The double quotes do something to the string inside.. For example this works:
echo "Hello $name";
but this just gives the variable name instead of it's contents:
echo 'Hello $name';
In other words it processes it's contents so use 's instead of "s around the $StoreID contents.
To be honest it might not even work so don't hold me to that. I ahve other suggestions but try this one first.
