make <select> NOT required if checkbox is checked

[jrahma]

Hi,

I have a PHP page.

I have MonthTo and YearTo <select> drop downs to display the month and year.

and I have chkPresent checkbox.

I want to make the MonthTo and YearTo required only when the checkbox is NOT checked.

How can I do this in PHP please?

Thanks,
Jassim

[johanafm]

Maybe by reading one of the other questions about this exact scenario that's been popping up over the last couple of days?