Hi Michael,

There is a difference between these two statements:

"I wish to check if the site URL is already the very first part of the string" (1)

And:

"I wish to check if the site URL exists anywhere in the string" (2)

Only (1) describes our intention and the only way to check _if the site URL is **not** already the first part_ is to check `0 !== strpos`.

This url, for example, will when decoded which it is in the ENV, make your code behave incorrectly:

```?id=1&returnUrl=http://mydomain.com```

Your code would make the condition TRUE and would not prefix the site domain. My suggested change to that expression makes sure the domain is prefixed even if it is also given as another argument's value.

Clear now?