I'll assume you might be using jQuery, since you didn't say. If not, then you can still take the concepts and port them to plain old javascript or whatever you're using.
Example markup
<form id="address-form">
<input type="radio" name="validate" id="validate_address" value="yes"> Validate<br>
<input type="radio" name="validate" value="no"> Don't Validate<br>
Street <input name="street"><br>
Suberb <input name="suberb"><br>
Postcode <input name="postcode"><br>
<input type="submit">
</form>
Conditional validation
Either somewhere on your page in a <script> tag or in a javascript file you include, create a submit event that will check the value of the radio input before doing the validation.
$('#address-form').submit(function(event) {
if ($('input[name=validate]:checked').val() === 'yes') {
if (!formValid()) {
event.preventDefault(); // Don't submit the form
}
}
});
// Perform validations
function formValid() {
if ($('input[name=street]').val().length == 0) {
// tell them ...
return false;
}
if ($('input[name=suberb]').val().length == 0) {
// tell them ...
return false;
}
if ($('input[name=postcode]').val().length == 0) {
// tell them ...
return false;
}
return true;
}
That should do the trick!
I created a jsfiddle you can mess with further if you want - http://jsfiddle.net/nilbus/JNnuX/2/
Using a checkbox instead
It's pretty similar to use a checkbox. Instead of this
if ($('input[name=validate]:checked').val() === 'yes') {
just check to see if your checkbox is checked.
if ($('input[name=validate]').attr('checked')) {
http://jsfiddle.net/nilbus/JNnuX/3/