How do set multiple entry relations using checkboxes on a front end form?
I'm pretty sure you can do this much simpler and without javascript. I've setup a front-end form using the doc's example and added checkboxes to choose entries that will be stored in a relational field simply by using name="fields[fieldName][]" in the input type="checkbox". For example:

&lt;input id="" class="" type="checkbox" name="fields[kitIcons][]" value="{{ entry.id }}" checked&gt;{{ entry.title }}&lt;br/&gt;


In the above example, "kitIcons" is the name of my relationship field, and I have this going through a loop to populate the entry.id and entry.title. Seems to be working without any glitches in my system.