Create a query for specified text in a field

Hi there,

I have a number of fields in my query. They are Customer, Document, Title.
In this query, i have include a input dialog for the user to enter the
customer name.
In the Customer field, there are several customers in one record that uses
the same document.
Example,

Customer | Document | Title
ABC/3H/SST | 12346 | This is a test procedure
ABC/3H | 11234 | Procedure

I would like the output shows a list of the documents used for the specified
customer. Example,
I want to know the list of documents that is for Customer: ABC so the output
will be

Customer | Document | Title
ABC | 12346 | This is a test procedure
ABC | 11234 | Procedure

For Customer : SST

Customer | Document | Title
SST | 12346 | This is a test procedure


How do I go about creating this scenario for this case? I tried to set the
criteria : Like "SST*" or Like "ABC*" under the Customer field but the output
shows everything and did not do a filter.

Pls help.

Thanks!