Regex to compare strings with Umlaut and non-Umlaut variations

Question

Can anyone help me with a javascript regular expression that I can use to compare strings that are the same, taking into acccount their non-Umlaut-ed versions.

for e

Answer 1

In addition to stereofrogs answer:

tr = {"\u00e4":"ae", "\u00fc":"ue", "\u00f6":"oe", "\u00df":"ss" }

ersetzeUmlauts = function(s) {
    return s.replace(/[\u00e4|\u00fc|\u00f6|\u00df]/g, function($0) { return tr[$0] })
}

I was dealing with Umlauts in an Aptana/Eclipse script and the normal characters ('ä' etc.) didn't do the trick for me.