Use CurrencyValidator to validate money values
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:CurrencyValidator source="{income}" property="text" allowNegative="false" negativeError="You pay your employer?" precision="2" precisionError="Just 2 decimals please." trigger="{submitButton}" triggerEvent="click" /> <mx:Text text="Money value:" /> <mx:TextInput id="income" /> <mx:Button label="Submit" id="submitButton" /> </mx:Application>