Asp.net mvc dropdownlistfor onchange event

List records = (from rcd in entity.AchievementType

where rcd.OrganizationID == orgid && rcd.RecordState == 0

select new Saras.SIMS.BehaviorMgmt.Entity.AchievementTypes

{

AchievementTypeId = rcd.Id,

Name = rcd.Name,

Points = rcd.Points

}).ToList();

I am returning this list to view as Model.AchievementTypes

Achievement type

@Html.DropDownListFor(m => m.AchievementTypeId, new SelectList(Model.AchievementTypes, "AchievementTypeId", "Name"), new { style = "width:100%" })

Weightage points

@Html.ExcelTextBox(m => m.Weightage, new TextBoxAttributes().SetMaxlength("5").SetCheckSpecialCharacters("True").SetReadOnly(false).SetCssClass("form-control"))

Now Onchange of AchievementType I want to bind the Points Value present in Model.AchievementTypes to Weightage

Can any one please suggest me how to do it.