Ajax - Beginning JavaScript - page 458

</td>
<td>
<a id="emailAvailability" href="#">Check Availability</a>
</td>
</tr>
<tr>
<td class="fieldname">
Password:
</td>
<td>
<input type="text" id="password" />
</td>
<td></td>
</tr>
<tr>
<td class="fieldname">
Verify Password:
</td>
<td>
<input type="text" id="password2" />
</td>
<td></td>
</tr>
<tr>
<td colspan="2" class="submit">
<input type="submit" value="Submit" />
</td>
<td></td>
</tr>
</table>
</form>
<iframe src="about:blank" id="hiddenFrame" name="hiddenFrame"></iframe>
<script>
function checkUsername(e) {
e.preventDefault();
var userValue = document.getElementById("username").value;
if (!userValue) {
alert("Please enter a user name to check!");
return;
}
var url = "ch14_iframevalidator.php?username=" + userValue;
frames["hiddenFrame"].location = url;
}
function checkEmail(e) {
e.preventDefault();
var emailValue = document.getElementById("email").value;
if (!emailValue) {
alert("Please enter an email address to check!");