AppleScript to Wrap Text in Quotation Marks

Fundamental mistake: I just tried to use an equals sign to set a variable in AppleScript.

Use words, not symbols.

My script is for taking some text and wrapping it in quotation marks.

Here is the script:

on run {input, parameters}
    set input to "“" & input & "”"
    return input
end run

Nothing difficult for today. I have set this as a Mac OS X Service receiving and replacing text from any application.