# Page not displaying

**URL:** <https://www.ruby-forum.com/t/page-not-displaying/130450>\
**Category:** Rails I18n\
**Created:** [February 28, 2008, 11:37am UTC](https://www.ruby-forum.com/t/page-not-displaying/130450 "2008-02-28T11:37:34Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ranjan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/35a633/32.png) [@ranjan](https://www.ruby-forum.com/u/ranjan)\
**Post date:** [February 28, 2008, 11:37am UTC](https://www.ruby-forum.com/t/page-not-displaying/130450/1 "2008-02-28T11:37:34Z")

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Hi,

I have following db schema:

Seminars (id, …)  
has\_many :seminars\_presentations  
has\_many presentations, :through =\> seminar\_presentations

Presentations (id, …)  
has\_many :seminar\_presentations  
has\_many :seminars, :through =\> seminar\_presentations

seminars\_presentations (seminar\_id, presentation\_id,…)  
belongs\_to :presentation  
belongs\_to :seminar

Now, I would like to implement as below:  
Assumption: Presentations & Seminars tables has few records.

I need to show the proposed (future) Seminar dates as links.  
To register an exisintg presentation to the seminar, the user clicks on  
a future date link. Then already registered presentations for that (just  
selected) seminar should be displayed and there should be option to add  
one more presentation to it.  
Once the user selectes a new presentation to register and clicks the  
“Register Presentation” link, that presentation should get registered  
with the seminar (from seminar date we can reach the seminar\_id and use  
it to register).

I have used Query string to get the proposed (future) Seminar date and  
then that date I use it to display on the view.

Now, my problem is when I try to add a presentation to the seminar,  
rails gives error nil.date. So, now I cannot register the presentation  
to the seminar.

Please help me.

Thanks.