JQuery :: Show / Hide Textfield After Changing In Dropdown List

I can't figure out why it dosen't work. I'd like to show/hide a <p> block depending on the value selected in the dropdown list:

$(document).ready(function(){
$('#report_rep_type').change(function(){
$('#report_rep_type').change(function(){
if($(this).text()!= 'Contigency Liabilities/Others')
$('#someElement').hide();
else
$('#someElement').show();
});
});
});

HTML code:
<form action="my action>
<fieldset>
<legend>Report details</legend>
<p>
<label for="report_rep_type">Report type</label><br />
<select id="report_rep_type" name="report[rep_type]"><option value="">Please select</option>
<option value="Scientific & Technical">Scientific & Technical</option>
<option value="Financial">Financial</option> .....
<p>
<button class="button " type="submit"><img alt="Tick" src="/images/silk/icons/tick.png?1245400388" /> Create</button>
</p>
</form>