I need help in check boxes like
there are two fields Gender ( Male or Female) So when I select the Male box it automatically crosses or blocks the female box.
Please help me and see the attachment is there any possibility.
The easiest way to do this would be to use a Radio Button Group ( only 1 can be selected so the code is done for you) you can change how they are styled so they look like your attachment.
From a programmatic standpoint radio buttons are for single item selections. Checkboxes are for multiple options. If you switch to the proper type of input your problem will be solved as @BarlaeDC suggests.