General question about checking a form field

[dwainehead]

I'm just curious which method you use to check the input is there, not how to validate or sanitize, but if you think 1 is better or why you use

if(!isset($_POST['txtField1'])
{
echo "Sorry that is a required field";
}

vs

if(empty($_POST['txtField1'])
{
echo "Sorry that is a required field";
}

it's just all about my making my code and clean and solid as possible.

Thanks

[Dan Grossman]

I use empty() for strings, which is both an isset() check and a length check.

You can't use empty() for a field where 0 is a valid input.

[STeeL_LT]

You should avoid empty() in this case. I use

if ((!isset($_POST['txtField1']) || ($_POST['txtField1'] == ''))
{
    echo "Sorry that is a required field";
}