How can I refer to a variable using a string containing its name?

You can use an eval to do it, though I try to avoid that sort of thing at all costs.

alert(eval(someString));

A better way, if you find yourself needing to do this, is to use a hash table.

var stuff = { myText: 'hello world!' };
var someString = 'myText';
alert( stuff[someString] );