open app-created html code in default bowser

Hi there…
I have my app create a text page and then save it as page1.html
This works fine. It also includes some custom fields which are important.
I give it a folderitem to the page
The problem happens when I try to use showurl(f) says that it cannot use these parameters.
Is there anyway around this that does not use htmlviewer? I want to open the code in page1.html in a new default browser window

ShowURL(“file://” + SpecialFolder.Desktop.Child(“page1.html”).NativePath)

2 ways it can be done:

//launches any filetype with its default app

//only opens a URL in the default webbrowser