dumb question about if statement

I feel really dumb asking this question, but for some reason I am not getting the syntax correct on this simple script:

if ("%AppFolder%"=="") then
DlgStaticText.SetProperties(CTRL_STATICTEXT_TOPINS TRUCTIONS,{Text="Sample Text"} );
end

If I take the DlgStaticText statement outside of the conditional, it works fine. But for some reason my blank %appFolder% is not being recognized as such, so the statement is never called when within the conditional.

%appFolder% is set on a previous screen using
SessionVar.Set("%AppFolder%","");

and I have verified that it at least appears to be blank when displayed.

What dumb thing am I missing

Thanks.

Scott