Ajax call not executed by button click in mvc4

Ajax call not executed by button click in mvc4

I am trying to refresh grid in partial view using AJAX call of button
click. But click method of button is not working properly.
Following code snippet is code i am using to execute
JQUERY
<script type="text/javascript">
$(document).ready(
function ()
{
$("#fromDate").datepicker({changeMonth: true, changeYear:
true });
$("#toDate").datepicker({changeMonth: true, changeYear:
true});
});
//function buttonClick() {
$("#btnSearch").click($.ajax({ url: 'Report/SearchGrid', type:
"POST", success: function (html) { } }));
//}
</script>
Razor Code
<input type="button" value="Search" id="btnSearch" onclick=
"buttonClick();" style="width: 90px; border: solid 1px #1570a6;
background-color: #1570a6; color: #FFFFFF; font-weight: 100;" />
Controller Code
public ActionResult SearchGrid(ExpenseReportModel model)
{
ExpenseReportModel expModel = new ExpenseReportModel();
expModel.ExpenseList = GetExpenseList();
expModel.ExpenseFromDate = Convert.ToDateTime(model.ExpenseFromDate);
expModel.ExpenseToDate = Convert.ToDateTime(model.ExpenseToDate);
return PartialView("_GridData", expModel.ExpenseList);
}