Validate a JavaScript function name

Question

What would be a regular expression which I can use to match a valid JavaScript function name...

E.g. myfunction would be valid but my<\\fun\\&g

Answer 1

in case Regular Expression is not a must..

function isValidFnName( name ) {
    try {
        eval('(function() { function ' + name + '() {} })()');
    } catch( e ) {
        return false;
    }
    return true;
}

isValidFnName('myfunction');     // true
isValidFnName('my<\fun\>ction'); // false