Using StringValidators in Flex.

packages to import:

import mx.events.ValidationResultEvent;
import mx.validators.Validator;
import mx.validators.StringValidator;

mxml Tag to use:

<mx:StringValidator id=”strVal” property=”text” />

on what control:

<mx:TextInput x=”256″ y=”10″ id=”txtuname” width=”206″ tabIndex=”1″/> 

ActionScript code to use:

strVal.source=txtuname;
strVal.required=true;
strVal.requiredFieldError=”Enter Your User Name”;
var bill_result1:ValidationResultEvent=strVal.validate();
if(bill_result1.type==ValidationResultEvent.INVALID)
{
txtuname.setFocus();
Alert.show(bill_result1.message,this.title);
}

Hope you understand the code.Enjoy the code.