Initialize an input (type="text") with the value of another input (type="hidden")? [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 9 years开发者_StackOverflow社区 ago.

Cannot use onload on the body tag.

---

<script>
    window.onload = function() {
        document.getElementById('id1').value = document.getElementById('id2').value;
    }
</script>