IsolatedStorageFileStream Enquiry

Hey all, I got a question in relation to the IsolatedStorageFileStream.... I was wondering how I capture the path of the document after my textbox displays the document name.

OpenFileDialog dlg = new
OpenFileDialog();
dlg.Filter = @"Picture File (*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp
| All Files (*.*)|*.*"
;
if
(dlg.ShowDialog() == true
)
{
txtFileUpload.Text = dlg.SafeFileName;
}

For example : I am able to do this using

FileStream (txtFileUpload.Text, FileMode.Open, FileAccess.Read);

But with IsolatedStorageFileStream, it would display FileNotFoundException.

So I was wondering, is there a way of which I could write IsolatedStorageFileStream much like the FileStream displayed above??

I am learning the C# language and I hope I could learn this as most of the examples that I have seen online have hardcoded the path like "MyFile.txt", which I do not wish for that.

Are there any tutorials or references of which I could refer in regards to IsolatedStorage?

Thank you for your time.