you have written
onclick="hhmm()"
that's why it doesn't work replace it with
onclick="GetValues()"
function GetValues() {
var Section = $('#ddSection option:selected').val();
var StartDate = $('#StartDate').val();
var EndDate = $('#EndDate').val();
alert('hi...............' + Section + '-' + StartDate + '--' + EndDate);
}
<asp:TextBox ID="StartDate" runat="server" ClientIDMode="Static"></asp:TextBox>
<asp:TextBox ID="EndDate" runat="server" ClientIDMode="Static"></asp:TextBox>
<asp:DropDownList ID="ddSection" Width="200px" runat="server" ClientIDMode="Static">
<asp:ListItem Value="Nirav">Nirav</asp:ListItem>
<asp:ListItem Value="Prabtani">Prabtani</asp:ListItem>
</asp:DropDownList>
<input id="Button2" type="button" value="Report" class="btn btn-success" onclick="GetValues()" />
try this i get both textbox value and dropdown value in alert, here i have bind dropdown manually for demo purpose check it.. :)