<!DOCTYPE html>
<html>
<head>
</head>
<body>
<form id="form_id" action="save_post.php">
<button id="button-id" type="submit">Form Button</button>
</form>
<script>
function submitForm()
{
document.getElementById("form_id").submit();
}
/*
run:
When click on 'Submit Form' save_post.php will be executed
*/
</script>
<button onclick="submitForm()">Submit Form</button>
</body>
</html>