Using Javascript to get values from fields and use in a different search

I am setting up a booked calendar search (and subsequent reservation) for an employee.

The employee can submit a "search" record (name, date/time in, date/time out, number of rooms). This is recorded.

Once submitted, I would like the date/time range to be used to undertake an actual search of a "booked/not booked" object and see if room(s) are available and return only the rooms that are available. I am trying to find the right way to collect the date/time in/out variables from the first submission to set the dates in the filters of the second search. I am open to javascript, I just haven't quite figured out the correct way to collect those record fields and use them accordingly.

Any help is much appreciated.