Bind using values from multiple hidden fields
When adding an "add to cart button" I would like to bind a column to the value of a combination of hidden fields.
For instance, I have a calendar that stores it's data in three hidden fields, one for day, one for month, and one for year.
I have a "DayNeeded" column in my ecart, and I would like to bind that column to the concatenated value of the 3 fields like this:
$_POST["selYear1"] . "-" . $_POST["selMonth1"] . "-" . $_POST["selDay1"];
I seem to be having problems getting this done. Binding to one value of one hidden field works fine, but I can't get it to bind like the above.