How I Add string lo list of model in javascript

I am trying to add strings in javascript to list of string in the model but nothing returning

public class  a
{  
  public a()
  {                
    myFamilyHiddenDropDown= new List<string>();
  }
  public List<string> myFamilyHiddenDropDown { get; set; }
}

View

@Html.HiddenFor(x => x.myFamilyHiddenDropDown)
<input id="next" type="submit" value="send"  /> 

$('#myFamilyHiddenDropDown').push("1");
$('#myFamilyHiddenDropDown').push("2");

Controller

public ActionResult a(a item)
{
}