return | NN 2 IE 3 ECMA 1
Stops execution of the current function. A return statement can be located anywhere within the function, including inside control structures. You can optionally specify a value to be returned to the calling statement. This return value can be any JavaScript data type. If a return statement that returns a value is in a loop or other control structure, there must be a return statement for each branch of the execution tree, including a default return statement if execution should reach the main execution scope near or at the end of the function.
Example
    function validateNumber(form) {
        var oneChar;
        for (var i = 0; i < userEntry.length; i++) {
            oneChar = form.entry.value.charAt(i);
            if (oneChar < "0" || oneChar > "9") {
                return false;
            }
        }
        return true;
    }