null or empty string

[Andrew Steady]

Hi,



I have written a dynamic validation routine which is based upon only
      validating the fields that have been submitted and then "mopping up"
      later. This only works because you can tell the difference

between a field being submitted and left blank (value = "") and a field not
      being present in the request (value = null).



This is true for input type="text" but is not true for input
      type="checkbox", has anyone come accross this problem before? any
      solutions ideas?



Cheers,



Andy S