Get previous items unique value in new add item form

Question

Hi
I have on list having items related to multiple locations.
Every location is related to one user.
When user logs in it filters the list with that users location.
Now when user click on add new item I want to get the data related to his location using item event listener.
But in new item form there is no way to get the location of that user in event listener as its new item.
So I passed the qury string parameter form list and changed the add item form link and form to get the query string paramter as default value in Add new Item form.
But again when user clicks on save button it redirects to original url without paramter. 
How to redirect user to url with parameter on click on Save/Cancel.
Is there any other way to get the previous item unique value in add new item from before executing the event listener?

Answer 1

Hi,
According to your post, my understanding is that you wanted to redirect user to url with parameter on click on Save/Cancel.
You need to modify the onclick event need to as below:
javascript: {{ddwrt:GenFireServerEvent('__redirect={{Home.aspx?Participant={@Participant}&@Activity={@Activity}}}')}}
Here is a similar thread for your reference:
http://social.technet.microsoft.com/Forums/en-US/b506cfe5-650e-4017-b470-9ca0a75cd390/sharepoint-2010-list-how-to-pass-parameters-in-a-url-to-another-page?forum=sharepointcustomizationprevious
In addition, you can creating an intermediate page which just finds the filed value with a DVWP and then redirect to RedirectURL with the filed value on the Query String.
For more information, you can refer to:
Redirect to Another Page from NewForm.aspx with the New Item’s ID
Best Regards,
Linda Li
Linda Li
TechNet Community Support