I have two RadDatePicker's. One holds a "date sent" value and another one a "date paid". The date sent value has to be before the date paid AND the date paid RadDatePicker has to be disabled until a date sent value has been set in a form. How would I achieve this? I thought a CompareValidator on the second control would prevent postback if the first input is empty but it seems that's not the case.
Help would be greatly appreciated.