form with slide up and downStuck need helping

i have a question form the questions are with radio buttons and when someone clicks ona radio button a new question slides up. but when i do it it keeps sliding about 4 times and it showing some of the divs which are meant to be hidden behind each other
help will be highly appreiciated.

<----i m using drupal webform ---->

<div class='question'><?php print drupal_render($form['submitted']['question1']); ?></div>
<div class='question'><?php print drupal_render($form['submitted']['question2']); ?></div>
<div class='question'><?php print drupal_render($form['submitted']['question3']); ?></div>

<----------HTML--------->

<div class="question">
<div id="webform-component-what-type-of-company-are-you" class="form-item webform-component webform-component-radios">
<label for="edit-submitted-what-type-of-company-are-you">
What type of company are you?
<span class="form-required" title="This field is required.">*</span>
</label>
<div id="edit-submitted-what-type-of-company-are-you" class="form-radios webform">
<div class="form-item form-type-radio form-item-submitted-what-type-of-company-are-you">
<input id="edit-submitted-what-type-of-company-are-you-1" class="webform form-radio" type="radio" value="key1" name="submitted[what_type_of_company_are_you]">
<label class="option" for="edit-submitted-what-type-of-company-are-you-1">Limited company </label>
</div>
<div class="form-item form-type-radio form-item-submitted-what-type-of-company-are-you">
<input id="edit-submitted-what-type-of-company-are-you-2" class="webform form-radio" type="radio" value="key2" name="submitted[what_type_of_company_are_you]">
<label class="option" for="edit-submitted-what-type-of-company-are-you-2">Partnership </label>
</div>
<div class="form-item form-type-radio form-item-submitted-what-type-of-company-are-you">
<input id="edit-submitted-what-type-of-company-are-you-3" class="webform form-radio" type="radio" value="key3" name="submitted[what_type_of_company_are_you]">
<label class="option" for="edit-submitted-what-type-of-company-are-you-3">Sole trader </label>
</div>
<div class="form-item form-type-radio form-item-submitted-what-type-of-company-are-you">
<input id="edit-submitted-what-type-of-company-are-you-4" class="webform form-radio" type="radio" value="key4" name="submitted[what_type_of_company_are_you]">
<label class="option" for="edit-submitted-what-type-of-company-are-you-4">Awaiting company registration </label>
</div>
</div>
</div>
</div>


jquery Code

$('document').ready(function () {
$(".question").not(".question:first").hide();

$('.form-item').click(function () {
$('.question:visible').slideUp().next().slideDown()
});

$('.prevbutton').click(function () {
$('.question:visible').slideUp().prev().slideDown()
});
});

$(document).ready(function () {
$(".question1").click(function () {
$(".nextbutton").show(100);
});

});

$(document).ready(function () {
$(".question2").click(function () {
$(".nextbutton1").show(100);
});

});

THANK YOU