Don
*NOT* use a text box to display your results.
Here is some reading for you, after which you should be able to bang this out in minutes.
Parameterized Queries[
^] - Great Post
Use that to get a data table and read this
DataGridView[
^]
Then look at this to run your queries in the background to not stop your thread
BackgroundWorker[
^]
Then tie into your textbox OnChange (or KeyUp depending on your requirements) to run the query in the background and populate the DataGridView.