checking if a cell is empty

Hi,
I need a condition in update form where before the form is updated, I have
to check if the value of a cell is empty or not. If it is not empty, an
error is shown and if empty, it is updated.
What I am doing wrong in the script ( $_POST['helper1_pos'] gets value from
the form). It shows error even if the cell is empty.

if (!is_null($_POST['helper1_pos'])) {
echo "Sorry! Helper 1 position already volunteered.";
exit;
}
else {
//update
}

Thanks.
Ashok.

Ashok wrote:
> Hi,
> I need a condition in update form where before the form is updated, I have
> to check if the value of a cell is empty or not. If it is not empty, an
> error is shown and if empty, it is updated.
> What I am doing wrong in the script ( $_POST['helper1_pos'] gets value fro
m
> the form). It shows error even if the cell is empty.
>
> if (!is_null($_POST['helper1_pos'])) {
> echo "Sorry! Helper 1 position already volunteered.";
> exit;
> }
> else {
> //update
> }


The proper way to check if a varaible is empty is by using the empty()
function, is_null only checks if the value of a variable is null.
Another good funcrtion to use here could be isset(), to see if there is a su
ch
varaible, before you check if it's empty or not.

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



//Aho