Searching the Database

I’m trying to setup a search form that when a product number (plu) is entered- the appropriate product will be displayed. I have the table setup containing the PLU numbers and the products.

I know it needs to be something similar to this- and I got some ideas from WPDB in the codex but still not quite getting it.

[Code moderated as per the Forum Rules. The maximum number of lines of code that you can post in these forums is ten lines. Please use the pastebin]

Any help would be greatly appreciated!