I've made a thread requesting something similar to this before (http://www.dynamicdrive.com/forums/s...d.php?p=122806)

Now I need to be able to do the same thing but so the URL they type in will be added to the end of an existing url.

For example the website address is www.site.net/---
But when the users put the url in the field and press go it will take them to www.site.net/---www.anothersite.com

Sorry if I'm not too clear at explaining this but does anyone have an idea of how to do this?