Better error when linking to username that doesn't exist

app/controllers/users_controller.rb

@@ -17,7 +17,11 @@ class UsersController < ApplicationController
   def index
     if params[:name].present?
       @user = User.find_by_name(params[:name])
-      redirect_to user_path(@user)
+      if @user.nil?
+        raise "No user found with name: #{params[:name]}"
+      else
+        redirect_to user_path(@user)
+      end
     else
       @users = User.search(params[:search]).order("users.id desc").paginate(params[:page], :limit => params[:limit], :search_count => params[:search])
       respond_with(@users) do |format|