What is the issue with deleting multiple entries using checkboxes in PHP and how can it be resolved?

Issue: The issue with deleting multiple entries using checkboxes in PHP is that the form data is not being processed correctly to identify which checkboxes are selected for deletion. To resolve this, we can iterate through the checkbox values and check if they are selected before deleting the corresponding entries.

```php
// Check if form is submitted
if(isset($_POST['delete'])){
    // Get array of selected checkbox values
    $selectedEntries = $_POST['checkbox'];

    // Iterate through selected entries and delete them
    foreach($selectedEntries as $entry){
        // Delete entry with $entry ID
        // Perform deletion operation here
    }
}
```
This code snippet shows how to process the form data correctly to identify selected checkboxes and delete corresponding entries in PHP.