IE, disabling options in <select>

[thesti]

hello,

i need to validate birthday using javascript. the validation is that for example user couldn't choose the date 29, 30 and 31 if she has chosen February as the month before and the year % 4 isn't 0.

i've done this with disabling the 29, 30 and 31 options in the select widget. here's the example code

document.register.birthday.options[31].disabled = true;

it works fine with Opera9.6 and firefox3.0.4 but, when i try it with IE6, the script doesn't work.

how to achieve this in IE, or is there any workaround for this for IE?

Thank you,
SC

[Logician]

I.E doesn't support disabling of options.
You could use the onchange handler to limit the selectedIndex to 28 on the appropriate month.