There is a better solution than the accepted answer, specifically using data-* attributes. Setting the id to 1 will cause you issues if any other element on the page has id=1. Instead, you can do:
<button class="btn btn-primary" data-toggle="modal" data-target="#yourModalID" data-yourparameter="whateverYouWant">Load</button>
<script>
$('#yourModalID').on('show.bs.modal', function(e) {
var yourparameter = e.relatedTarget.dataset.yourparameter;
// Do some stuff w/ it.
});
</script>