How do you call a function defined in .bashrc from the shell?

In my .bashrc, I have a function called hello:

function hello() {
   echo "Hello, $1!"
}

I want to be able to invoke hello() from the shell as follows:

$ hello Lloyd

And get the output:

> Hello, Lloyd!

What's the trick?

(The real function I have in mind is more complicated, of course.)

EDIT: This is REALLY caused by a syntax error in the function, I think! :(

function coolness() {

    if[ [-z "$1"] -o [-z "$2"] ]; then
        echo "Usage: $0 [sub_package] [endpoint]";
        exit 1;
    fi
        echo "Hi!"
}