strip out wierd characters in a string

Hi Guys, I think that a string that I'm grabbing from a website was actually created using ms-word. If I echo the string out, it has a question mark in it. If you look at the website, the text is fine ie"string some more text" but when I grab it from the website, and then echo the string, I get. "string? some more text" I have tried doing this echo str_replace("?", " ", $text); but it still print's out the ?. I think it's because the string itself has a wierd binary character in it or something. Anyone know how to fix this? Thanks, Brent