valid date from a form

[meHere]

How do I check that a date entered from a form is valid and if not keep telling the user it is invalid until they enter a valid one?

I know that there is a check date function but my problem is where do I put it ?

I have tried down where the form is and a function of its own but it doesn't work. any ideas? thanks in advance

[dalecosp]

Generally, to test an input, you will use [man]ereg[/man] or [man]eregi[/man], or if you prefer PCRE* over POSIX Standards, [man]preg_match[/man].

If you are reasonably sure that they are inputting the date in a readable format (say, for example, you're using HTML selects instead of text inputs) then you would simply test the value of checkdate in your handler script.

if (!checkdate($_POST['month'], $_POST['day'], $_POST['year'])) {
     die("The date is not valid.");
}

*PCRE = "Perl Compatible Regular Expressions", which use a different syntax and are said to be faster .... I barely get by with POSIX Std, myself....