How to loop through $_POST passing each post field as a parameter to a function?Edit [closed]

Answer 1

One sample loop to get both the array keys & values:

foreach( $_POST as $key => $value )
{

    isvalid( $key, $value );

}

... so you need to change your isvalid() function to accept two parameters if you need to get the field1, field2, etc.

EDITED

$errors = array();    

foreach( $_POST as $key => $value )
    if ( empty( $value ) ) $errors[] = $key;

if ( !empty( $errors ) )
    echo 'You have errors on: 
' . print_r( $errors, true ) . '
';

... you can cancel the submit if $errors is not empty.