Security - Input Validations

Question

For security -  Stored XSS - I have recevied following recommandation 

 

"Input validation should be performed on all parameters." 

 

In my application I am saving record using ajax call.

 

E.g. Saving Fund Record I have Fund Name and Fund Value

Both are HTML input conrols.

 

I am making Ajax call to server webmethod and saving data in database how do I incorporate above recommndation.

 

Oneway to make utilty method pass all inputs to method and validate it.

But its lot of work to call validation method in all webmethod.

 

Any inputs/ideas will be appreciated. Thanks in advance.