将下拉列表的值传递到文本框

我的视图中有一个下拉列表、一个提交按钮和一个文本框。我想在单击提交按钮或 dropdownlist 的 onChange 事件时将 dropdownlist 的选定值传递到文本框。我怎样才能实现这个目标？

我解决如下：

<script type="text/javascript">
    $(function() {
        $('#ddlComp').change(function() {
            var selectedValue = $(this).val();
            $('#txtCompName').val(selectedValue);
        });
    });
</script>

<div>
    @Html.DropDownList("ddlcomp", Model.CompanyList)
    <input type="submit" value="Submit" />    
    @Html.TextBox("txtCompName")
</div>

I want to pass the selected value of dropdownlist to the textbox when the submit button is clicked or onChange event of dropdownlist

$(function() {
    var selectedValue = ''; // declare variable here

    // on drop down change
    $('#ddlComp').change(function() {
        selectedValue = $(this).val(); // store value in variable
        $('#txtCompName').val(selectedValue); // update on change
    });

    // on submit button click
    $('input[type=submit]').click(function(){
        $('#txtCompName').val(selectedValue); // update on submit button
    });
});