How to disable a checkbox when another one is checked?

Hi everyone!


I'm a beginner in Nav. I'm working with Nav 2009 R2. I have two checkboxes in a form (male, female). Once you select a determined gender,for example, female,  I want to disable the male checkbox.  If you then uncheck the female checkbox I want the male checkbox to be enabled again. I hope that I expressed myself clearly because I'm new at this Wink

Thanks in advance for your help!!