setelement=function(fdef,value,idx)

set the value to an element in a form. If using the idx parameter, you set a value to a sub form element based on id is in the form name_idx

Parameters

- fdef : this if the definition from a element in a recorddef

- value : the value to set in the element

- idx : the index into a subform, if the idx in undefined, this is a main form