This is the exact if statement I am trying to use:<BR><BR>if((document.Admin.Month.value=="Feb") && (document.Admin.Year.value % 4==0 && document.Admin.Year.value % 400==0) && (document.Admin.Day.value &#060; 1 &#124&#124 document.Admin.Day.value &#062; 29))<BR><BR>{<BR>alert(&#039You have not entered a valid DAY for the month of &#039+document.Admin.Month.value+&#039 in the Date portion of this form.
Please enter a DATE between 1 and 29 for which the Property Tax information is valid.&#039); return(false);<BR>}<BR><BR>It checks sucessfully for the Month (Feb) and if the Year is divisible by 4. So, Feb 29 2000 is valid, but Feb 29 1999 is not. But, it seems to fail when checking if it is divisible by 4000. Feb 29 2100 should not work, yet it seems to pass this test.<BR><BR>Any ideas?<BR><BR>Thanks.