Load Dropdown select onchange @Html.DropDownList using jquery in mvc

@Html.DropDownList("StyleColor", ViewBag.Colors as SelectList, "---Select Color---", new { @class = "form-control", @id = "StyleColor", onchange = "LoadCompo()" })

$("#StyleColor").change(function() {
    var composition = $("#RawMaterialName").val();
    Load(composition);
});

function LoadCompo(parameter) {
    $.ajax({
        url: _urlBase + 'yourUrl',
        data: { 'CatName': parameter },
        success: function(data) {
            $("#RawMaterialName").empty();
            $.each(data, function(key, value) {
                $('#RawMaterialName').append($("<option></option>").val(value.RawMaterialName).html(value.RawMaterialName));

            });
            //$('#UnitName').val(value.PRD_UnitType.UnitName);
        },
        error: function() {
            alert('An error occured try again later');
        }
    });
}