How to assign html title from variable with vbscript?

How to assign html title from variable with vbscript?

I'm currently trying to get a modal window to set my html <title> from a
vbscript function like this:
<title> <%foo.bar%> </title>
where foo.bar
Function bar() as string
bar = "some text"
end function
This gives no success.
I also tried the below snippets, but without success. It throws "An
unhandled exception" for incompatible types.
<%@Language=VBScript%>
<% barVar = "fooFoo" %>
<title><%barVar%></title>
Does anyone know what possibly could be the problem here? Thanks for reading.