var values = "554,20".split(",")
var v1 = parseFloat(values[0])
var v2 = parseFloat(values[1])

var value = parseFloat("554,20".replace(",", "."));

var str = '3.8';ie
alert( +(str) + 0.2 );

var floatValue = +(str.replace(/,/,'.'));

var value = parseFloat("554,20")

var value = parseFloat("554.20")

var fValue = parseFloat(document.getElementById("textfield").value.replace(",","."))

String.prototype.float = function() {
  return parseFloat(this.replace(',', '.'));
}

"554,20".float()
> 554.20

"554.20".float()
> 554.20

typeof "554,20".float()
> "number"

var str = '6.000.000';
str.replace(/[.]/g,",");