How to execute a JavaScript function when I have its name as a string

specialexec.js

// http://stackoverflow.com/questions/359788/how-to-execute-a-javascript-function-when-i-have-its-name-as-a-string
function Exec(functionName, context) 
{
	if(typeof functionName === 'undefined')
	{
		console.error('Could not execute undefined function');
		return function() {}
	}

    var args = Array.prototype.slice.call(arguments, 2);
    var namespaces = functionName.split(".");
    var func = namespaces.pop();

    for (var i = 0; i < namespaces.length; i++) 
    {
        context = context[namespaces[i]];
    }

    return context[func].apply(context, args);
}