Releasing Excel COM Object Method?

Well, I've searched numerous threads and I'm stumped. Though my VB.net experience is newb status.I'm interacting with Excel Workbooks/worksheets with:

Imports Excel = Microsoft.Office.Interop.Excel

Now I'm fairly adept with getting data from the excel sheet with no problem.But each and every time I quit my widows form, or execute a new command_button click to repeat an operation, in the task manager, excel.exe then opens up a new instance.Releasing the the Excel COM object seems to offer a bit of head scratching.I realize that you can get your form to activate and retrieve data from whatever spreadsheet has been directed to be opened, but I can't seem to put it back and close it correctly.I have read about the Marshal. release object methods and garbage collection with no luck so far.Do I need to import another liberary that completes this operation? I would asssume this would be taken care of as apart of the:

Imports Excel = Microsoft.Office.Interop.Excel

close excel instances opened up by my windows form? Somethig like this:

Dim xlApp As Excel.Application
Dim xlWorkBook As Excel.Workbook
Dim xlWorkSheet As Excel.Worksheet

[code]....

(so that it is no longer looked at as "read only" when the spread sheet is opened up from directly from excel)As A minor work around, I've teminated it from the task Bar with proc.kill() but this does not help because my ultimate goal is to just simply realease the excel sheet when my windows form is finished getting its data.This following code does not seem to work.

releaseObject(xlApp)
releaseObject(xlWorkBook)
releaseObject(xlWorkSheet)