Return blank input field with a value help

[double_cola]

Hey guys!
Im putting together a drag and drop page where a user will drag an ellement (in this case and printable pdf) over into a print field.
I need blank fields on the right to return either as (void skip this) or with default pdf.
Any ideas?

Here is the page Click Here

[double_cola]

I answered my own questin incase someone needs to know. When validating the form I used

$item= $_POST['itemOrder'];
if( $item == "")
{
    $item= "";
};

If that doesnt make sense feel free to message me and I can help explain.