diff --git a/app/views/seminars/con_upload.html.erb b/app/views/seminars/con_upload.html.erb
index b753c40..d184fb4 100644
--- a/app/views/seminars/con_upload.html.erb
+++ b/app/views/seminars/con_upload.html.erb
@@ -70,11 +70,11 @@
 				<% end %>
 				<td>
 					<%= link_to t(:edit), prefix_url + '?method=edit_file&con_no=' + seminar_signup_contribute.id, :class => 'btn btn-primary' %> 
-					<form method="post" action="<%= del_file_seminars_path %>">
-	  					<%= submit_tag t(:delete_), class: "btn btn-primary" %>
-	          			<input type="hidden" name="referer_url" value="<%= request.original_url.split(request.env["HTTP_HOST"]).last.split('?').first %>">
-	  					<input type="hidden" name="con_no" value="<%= seminar_signup_contribute.id %>">
-					</form>
+					<%= form_with url: del_file_seminars_path, method: "post" do |f| %>
+					  <%= f.submit_tag t(:delete_), class: "btn btn-primary" %>
+					  <%= f.hidden_field_tag "referer_url", request.original_url.split(request.env["HTTP_HOST"]).last.split('?').first %>
+					  <%= f.hidden_field_tag "con_no", seminar_signup_contribute.id %>
+					<% end %>
 
 				</td>
 			</tr>