Mask edit field validates the text the user enters against a mask that encodes the valid forms the text can take. The mask can also format text that is displayed to the user.

Mask character	Meaning in mask
l	Mixed case letter character [a..z, A..Z]
L	Upper case letter character [A..Z]
a	Mixed case alpha numeric character [a..z, A..Z, 0..1]
A	Upper case alpha numeric character [A..Z, 0..9]
#	Numeric character [0..9]
_	Reserved character for display, do not use.
others	Non editable character for display.

Body: removed
Informal parameters: not allowed
Reserved parameters: none

This example provides a credit card payment page.

<form jwcid="paymentForm">
 <table cellpadding="4">
  <tr align="left">
   <td colspan="2"><font color="blue"><i>Please enter your credit card details and click 'Pay'.</i></font><p/></td>
  </tr>
  <tr align="right">
  </tr>  
  <tr><td>Card Number:</td><td><input jwcid="cardNumberMaskEdit"/></td>
  </tr>
   <tr><td>Expiry Date:</td><td><input jwcid="cardExpiryMaskEdit"/></td>
  </tr>
  <tr align="right">
   <td>&nbsp;</td><td><input type="submit" value="  Pay  "/></td>
  </tr>
 </table>
</form>


<component id="paymentForm" type="Form">
   <binding name='listener' expression='listeners.formSubmit'/>
</component>

<component id="cardNumberMaskEdit" type="contrib:MaskEdit">
   <binding name='value' expression='cardNumber'/>
   <binding name='mask' expression='"####-#####-####-####"'/>
</component>

<component id="cardExpiryMaskEdit" type="contrib:MaskEdit">
   <binding name='value' expression='cardExpiry'/>
   <binding name='mask' expression='"##/##"'/>
</component>


public class PaymentPage extends BasePage {
    private String cardNumber;
    private String cardExpiry;
    
    protected void initialize() {
       cardNumber = null;
       cardExpiry = null;
    }
    
    public String getCardNumber() { return cardNumber; }
    
    public void setCardNumber(String value) {
       cardNumber = value;
    }

    public String getCardExpiry() { return cardExpiry; }
    
    public void setCardExpiry(String value) {
       cardExpiry = value;
    }

    public void formSubmit(IRequestCycle cycle) {
        // Process form submission and make payment
    }
}