Find() fuction is as?

EDIT: forgive my typo in the subject…:disco:


I need to know if actionscript has a find() fuction:

The function needs to remove anything after the ? in a url (including itself) if a ? is present.

Kind of like:
index = Find(_root.page, “?”)
if (index > false) {
thePage = left(_root.page, index)
} else {
thePage = _root.page
}

Can anyone help?