how to put the selected value of drop down to textbox

Question

I need to select the value of dropdownlist and put it on textbox I tried theses but not working 

 

$('#<%= DDL_ID.ClientID %>').change(function() {     $('#<%= TextBoxID.ClientID %>').val($(this).val()); });

 

 protected void DDL_SelectedIndexChanged(object sender, EventArgs e) { var selectedValue = ((DropDownList)sender).SelectedValue; TextBox1.Text = selectedValue; }