[jQuery] mootools - jquery conversion

Hi to all,
I have a project that was coded in mootools, but I want to use jquery.
Anyone knows how to convert the following code to jquery? or where I
could find a freelance to make the conversion.
--------------------- code start ----------------------
function changeState (value, childSelectId) {
new Ajax('/lab/selections/options/' + value, {method: 'get',
onComplete: function( response ) {
respObj = Json.evaluate( response.substring(0,
response.indexOf('<b>Fatal error</b>')) );
if(respObj.attributes.length == 0) {
    $node = $('text_' + childSelectId).getParent();
        $node.setStyle('display', 'inline');
$('text_' + childSelectId).setStyle('display', 'inline');
     $('select_' + childSelectId).setStyle('display', 'none');
} else {
$node = $('text_' + childSelectId).getParent();
     $node.setStyle('display', 'inline');
$('select_' + childSelectId).empty();
     $('select_' + childSelectId).setStyle('display', 'inline');
$('text_' + childSelectId).setStyle('display', 'none');
     respObj.attributes.each(function(attribute) {
if(attribute.name == 'notextline') {
     $node = $('text_' + childSelectId).getParent();
         $node.setStyle('display', 'none');
$('ezcoa-' + childSelectId).value = '';
} else {
var newOption = new Element('option', {'value':
attribute.name});
newOption.setHTML(attribute.name);
newOption.inject($('select_' + childSelectId));
}
});
}
}}).request();
}
function sel_text(object){
return object.options[object.selectedIndex].getText();
}
function changeSelect(select_id,hidden_id)
{
$(hidden_id).value= $(select_id).options[$
(select_id).selectedIndex].value;
}
function changeInput(input_id,hidden_id)
{
$(hidden_id).value= $(input_id).value;
}
--------------------- code end ----------------------