Dynamic Web Page, Generate <select> Dynamically Options

[joehesse]

I have an html page, generated with php and mysql, that has an html table of real estate properties. The table has a hidden column. The cells in the hidden column contain folder paths. Each folder contains pdf, jpeg, and text files relvant to the real estate property in the row.

How do I do:
When a row is selected by the user, I want a <select> tag to appear listing the file names in the folder. I know how to write a php function that takes as input the folder name and generates the html <select> of files in the folder. I don't know how to make the <select> appear next to the table.

How do I do:
When the user selects an item (file) from the <select> tag, the file should open in a different browser tab.

Any pointers as to what I should look at would be much appreciated.

Thank you,
Joe