validating an optional field

Anon

I have a form that the user can enter several fields. Two of these fields are Start Date (date) and Closed Date (closed). date is a required field and is validated using ereg without any problems. closed is optional and thats where my problem lies. I am basically trying to embed an if else statement within an if statement. I have tried this every possible way I can think yet I am having no luck. It eatheir gives me the "wrong format" error if the date is left blank or accepts any format at all. Here is a snippet of the code I am using. All variables are defined in a form on the previous page:
if ($closed!="") $checkdate="true";
else $checkdate="false";
if($checkdate="true"){
if(ereg('[0-9]{2}\/[0-9]{2}\/[0-9]{4}',$date));
else{header("Location:http://givenhost/baddate.html");exit;} }

I basically want it to check to see if $closed got populated and if it did I want it to check and make sure that it is in the MM/DD/YYY format. I realize this is probably available somewhere on the internet or in a manual but I have not been able to find it. Perhaps my mind is just fried from staring at this for so log. If anyone could possibly offer up a suggestion or, better yet, a solution I would be eternally grateful. I sincerely apologize if this is some sort of frequently asked question. Thanks.

Anon

also... where I have $date in the ereg is because I copied from the wrong place. it actuallt should be $closed.

yelvington

http://www.php.net/manual/en/function.isset.php

if (isset($somevariable))
{
// insert your validation code here
}

Anon

Hey Steve! Thanks for the link to the manual... I never would have thought to look at the instructions for the proper code.

Actually I have it printed out and it sits by my computer and I reference if often. I posted my question as a last resort because I couldn't figure out why I was having the problem I was having. The isset didn't work for me. I did finally got it to work using the $somevariable != "" similar to what I had posted in my original snippet of code. . Again, thanks for the link!!

Steve Yelvington wrote:

http://www.php.net/manual/en/function.isset.php

if (isset($somevariable))
{
// insert your validation code here
}