JavaScript Form Submit - Confirm or Cancel Submission Dialog Box

For a simple form with an alert that asks if fields were filled out correctly, I need a function that does this:

• Shows an alert box when button is clicked with two options:

  • If "OK" is clicked, the form is submitted
  • If cancel is clicked, the alert box closes and the form can be adjusted and resubmitted

I think a JavaScript confirm would work but I can't seem to figure out how.

The code I have now is:

function show_alert() {
  alert("xxxxxx");
}

<form>
  <input type="image" src="xxx" border="0" name="submit" onclick="show_alert();" alt="PayPal - The safer, easier way to pay online!" value="Submit">
</form>

A simple inline JavaScript confirm would suffice:

<form onsubmit="return confirm('Do you really want to submit the form?');">

No need for an external function unless you are doing validation, which you can do something like this:

<script>
function validate(form) {

    // validation code here ...


    if(!valid) {
        alert('Please correct the errors in the form!');
        return false;
    }
    else {
        return confirm('Do you really want to submit the form?');
    }
}
</script>
<form onsubmit="return validate(this);">