In asp.net mvc How do i use htmlDropdownlist with selected value and onchange event?

How do i load the dropdown list with a selected value there is 开发者_如何学编程a also an onchange event?

List<SelectListItem> environments = new List<SelectListItem>();

environments.Add(new SelectListItem { Text = "Development", Value = "DEV"});
environments.Add(new SelectListItem { Text = "Staging", Value = "STA" });
environments.Add(new SelectListItem { Text = "SNL", Value = "SNL"});
environments.Add(new SelectListItem { Text = "Production", Value = "PROD" });

 ViewData["Environments"] = new SelectList(environments, "Value", "Text", environment);

<p>Select a Deploy to: <%=Html.DropDownList("Environments", (SelectList)ViewData["Environments"], new { onchange = "this.form.action='DeployToChanged';this.form.submit()" })%></p>

are you talking about having one pre-selected when the page loads?

new SelectListItem { Text = "..", Value = "..", Selected=true}