Wildcard character available in asp classic? - if-statement

Question

I'm got a site with classic asp using vbscript. How can I check if a user is coming from a certain directory on my site? I've got this code
<%Response.Write(Request.ServerVariables("http_referer"))%>
which writes: http://example.com/mobile/REFER.asp. I'd like to write an if/else statement that first checks if the referring uri is in the directory http://example.com/mobile/.
So my code should be something like the below. But I'm not sure about syntax. Is there such a thing as a wildcard character is asp?
<% Request.ServerVariables("http_referer") == "http://example.com/mobile/*"
Eventually I'd like to use that to write an if /else statement
<% if Request.ServerVariables("http_referer") != "http://example.com/mobile/*" then
null; elseif (screen.width <= 699) {
document.location = "/mobile/mobile_home.asp";
} %>
===
Ended up editing #mikeyq6's javascript sample to this which works:
<script type="text/javascript">
if(document.referrer.indexOf('/mobile') > -1 &&
screen.width <= 699) {
document.location = "/mobile/mobile_home.asp";
}
</script>

Answer 1

You know the length of the fixed url you are looking for so just see if the first n characters of the referer match it:
const BASE_DIR = "http://example.com/mobile/"
dim referer: referer = lcase(Request.ServerVariables("http_referer"))
if left(referer, len(BASE_DIR)) = BASE_DIR then
...
else
...
end if

Answer 2

Essentially what you are dealing with is a string, so you can't use wildcards in this way (unless you were to use regular expressions, which is like hitting a nail with a sledgehammer in this case)
It would be much easier to use the InStr function to check to see if the value contains the string you are looking for. Eg:
<% if InStr(Request.ServerVariables("http_referer"), "http://example.com/mobile/") = 0 then
null
elseif (screen.width <= 699) {
document.location = "/mobile/mobile_home.asp";
} %>
More info on InStr here:
http://www.w3schools.com/asp/func_instr.asp
You can do something similar in javascript as well:
if(window.location.href.indexOf("http://example.com/mobile/") > -1 &&
screen.width <= 699) {
document.location = "/mobile/mobile_home.asp";
}
Notice that I simplified the if...else as well. You don't need both cases.