Question File is always downloaded if it contains javascript

[droidman]

I'm hosting a script on my server that replies with some javascript, when i try to open the page on webbrowser, it tries to download the response.js instead of showing its text.
I tried using "client.DownloadString" but it says that i dont have the login done, also tried using the Mozilla Framework but it kept crashing visual studio.
Is there a way to download the file and showing it on a textbox? i need it to use the normal webbrowser, (ie) since it needs the session to be logged in on the server

Thanks in advance