How to fire OnClick with disabled controls?

[John Walker]

Hi,
In my ASP.NET datagrid I have a TemplateColumn which contains an
asp:Checkbox control. Sometimes this checkbox will be disabled, and when it
is disabled, when the user tries to click on it, I would like to popup a
Javascript alert that says something like, "You can't check here till you
fill in the delivery date!", but when the checkbox is disabled, the OnClick
event won't fire. Is there a way around this?

Thanks,
John