how to value retrive in link button

 <asp:LinkButton runat ="server" CssClass ="btn" ID ="lnkapply" OnClick="lnkapply_Click" Text ="Apply" CommandArgument='<%# Eval("CareerID") %>'  ></asp:LinkButton>


 protected void lnkapply_Click(object sender, EventArgs e)
        {
          LinkButton aply = (LinkButton)sender;
          var apply= aply.CommandArgument;
          ViewState["applyview"] = apply;
          mvCareer.ActiveViewIndex = 0;
        }