Adding quotes around a text field

I have a text field where people enter tags and click a button to
submit. Some of the users are entering multiple tags accidentally (i.e.
‘really’ and ‘cool’ instead of ‘really cool’) so I’d like to alter my
code so it automagically adds quotes on either side of whatever they
submit. I haven’t the foggiest idea where to start… Here is the code
I’m working with:

<%= start_form_tag :controller =>‘stores’, :action => ‘updatetags’ %>
<%= text_field ‘store’, ‘store_tags’ %>
<%= submit_tag “Add” %>
<%= end_form_tag %>

Can anyone help me?