$(document).ready(function(){
 
  // Initial setting
  if($('.question1342 input.radio:checked').attr('value') == '1') {
    $('#variableimage').attr('src', 'http://www.springboltconsulting.com/surveyassets/images/demo_image1.png');
  }
 
  // Listener on the radios
  $('.question1342 input.radio').click(function(event){
    var clickedvalue = $(this).attr('value');
    if(clickedvalue == '1') {
      $('#variableimage').attr('src', 'http://www.springboltconsulting.com/surveyassets/images/demo_image2.png');
    }
    if(clickedvalue == '2') {
      $('#variableimage').attr('src', 'http://www.springboltconsulting.com/surveyassets/images/demo_image3.png');
    }
    if(clickedvalue == '3') {
      $('#variableimage').attr('src', 'http://www.springboltconsulting.com/surveyassets/images/demo_image4.png');
    }
  });
});