Display name in Data Entity framework

I'd like to know how to change the display name of a model, and customize error messages in Entity Framework. I tried the following but it didn't work. ``` [Required(ErrorMessage = "Required .... :")] [Display(Name = "Name Agency : ")] [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.String Nag { get { //code } set { //code } } ``` This is the code behind my form that adds data into my database. I've omitted irrelevant lines. ``` <% using (Html.BeginForm("addcar", "Agence", FormMethod.Post, new { @class = "search_form" })) { %> <%: Html.ValidationSummary(true) %> <div class="editor-label"> <%: Html.LabelFor(model => model.Dmcv) %> </div> <div class="editor-field"> <%: Html.EditorFor(model => model.Dmcv) %> <%: Html.ValidationMessageFor(model => model.Dmcv) %> </div> <div class="editor-label"> <%: Html.LabelFor(model => model.Puisv) %> </div> <div class="editor-field"> <%: Html.EditorFor(model => model.Puisv) %> <%: Html.ValidationMessageFor(model => model.Puisv) %> </div> // Similaire code <p> <input type="submit" value="Create" /> </p> <% } %> ```