Getting handle on Web Site content

Hi All, How would it be possible to take detail from a web site that I have opened and use it in my own app? A simple example would be when I open a web site and see 5 textboxes with different detail in and when I select a button on my app that it would take the current web page open and capture the data from those 5 textboxes in variables in my app to use through out my app? Thanks,