EDIT - I think this is working now - had missed a couple of field name references that needed changing.
One question though - what code would I need to get it to select all, or clear all?
I thought from somewhere it may just be:
<input type="button" name="check" value="Select All Contacts" id="check" onClick="check_all(boxes, check_box);" />
<input type="button" name="uncheck" value="Clear All Checkboxes" id="uncheck" onClick="uncheck_all(boxes, check_box);" />
But that doesn't seem to be working.
var check_box = new Array();
var boxes = 0;
in the header, and:
check_box[boxes] = "LodgeIDPL_<?php echo $RepeatSelectionCounter_1; ?>";
boxes += 1;
in the form.
Although that still isn't working.