i've a field, which is validated client side in validation.xml..
But i want to make a generic validation.xml so that only when a particular field(say username) is present, it should validate, otherwise no need to validate..
But the code for the validation always remains there, for the field..If its present it ll validate, otherwise no... but in validation.xml, it wont support any condition like
(if username)
code for validate..

thank you in advance for a solution