Problem
Delete all the rows added in the Form Grid when a field value is changed.
Code
<script>
$(document).ready(function(){
var selectField = "field1";
var formGrid = "field2";
//when select box value is changed
$("[name="+selectField+"]:enabled").change(function(){
//remove all data from form grid
$("[name="+formGrid+"]").find("table tr.grid-row").remove();
});
});
</script>