How to launching Acrobat Reader outside IE

[1234shu]

I need to open a pdf file in Adobe Reader itself instead of inside IE. I prefer to use JavaScript or any other language to achieve this instead of change the configuration of the acrobat itself.
The issue we want to deal with is on the pdf file there is a button for user to close the file. When the user clicks the button, there is a javascript confirm, if the user confirms the close, the file is supposed to close. The button functions well when it's opened in Adobe Reader but doesn't work when it's open inside IE with Adobe Reader. Thanks a lot for any help.