How to insert user inputed form element into If objFs.FileExists?

Hi, so i have been making my first small application and i got stuck here...
I dont know how to take a user input from form and then make the
If objFs.FileExists("?????") Then
check if the file with that name exists or not
ts.WriteLine "SET GIFNAME=" & document.Forms(0).elements("gifname").value
basically i dont know how to connect these two
what ever i put in the "?????" place doesnt work.
I need to check if the name (file) that the user selected in the form input exists or not
can someone please help me?
 

What exactly did you put in the "?????" place? And how exactly did it "not work"?

Kept testing and testing...got it fixed with:
 
   strName = strName & ".gif"
   strPath = myCur & "\Output\" & strName
 
Thx for responding anyway