Asp.net Mvc Html Helper listboxFor click event

Question

How do I call onclick when the user clicks in asp.mvc 5. The below code doesnt work

   @Html.ListBoxFor(m => Model.DepDashTaskLists[i].BusinessRuleQuestion1Answer, new MultiSelectList(slh.GetRegistrationAnswerLookup(Model.DepDashTaskLists[i].BusinessRuleQuestion1), "Value", "Text", Model.DepDashTaskLists[i].BusinessRuleAnswers), new { @onclick="somefunction()",  @id = "RuleQuestionListBoxAnswer", @class = "listbox" })

Answer 1

Have some javascript which listens to the click event on the listbox and get the item text and set as the value of the other textbox

@Html.ListBoxFor(x => x.ItemId, new MultiSelectList(Model.ListOfItems, "Text", "Value", Model.ItemId), new { size = 6, id = "itemsList", OnChange = "showText" })
$(function(){

  $("#ItemId option").click(function () {
    var _this = $(this);
    $("#txtItem").val($(_this).text());
  });

});

Working sample: http://jsfiddle.net/w4sxw/