[jQuery] Error-Message: is not a function

[Sen]

Hi,

I've been thinking the last two hours about this problem:
The following function is part of a form validation script. The
targeted selects contain a name attribute like "accomodation[1]" or
"accomodation[2]". I neet the number within the brackets. The alert-
function is just for testing and will be replaced later on by the
processing of catid.
I constantly get the errormessage "catid.replace is not a function"
pointing to the line containing the first .replace.

function checkacc() {
        var catid;
        var places;
        var err;
        err = 0;

        $("select[name^='accommodation']").each( function() {
                        catid = $(this).attr("name").match(/\[.+\]/);
                        catid = catid.replace(/\[/,"");
                        catid = catid.replace(/\]/,'');
                        alert(catid);
                        err = 1;
                }
        );
        return err;
}

Can some one help me please?

And then I'm confused about the "this"-Syntax. I thougth that I can
use it like this: this.attr... but then I get an is-not-a-function-
error too. (By the way: $(catid) produces the same error).

Thanks,

Jan