i'd like to pop up a form when click a link.

```
<a title='%s' onclick='return popupform()'  href='#'> ABC </a>

```

the form is like:

```
<form id="contactus" action="javascript:submit_form()" method="post" accept-charset="UTF-8">
<input type="hidden" name="submitted" id="submitted" value="1">
    <label for="chinese">Chinese: </label><br>
    <input type="text" name="cs" id="cs" value="" maxlength="50"><br>
<label for="english">English:</label><br>
    <input type="text" name="en" id="en" value="" maxlength="50"><br>
    <input type="submit" name="Save" value="Save">
    <input type="submit" name="Delete" value="Delete">
    <input type="submit" name="Add" value="Add">
    <input type="submit" name="Close" value="Close">
</form>

```

how to achieve it?