function  toggleCheckboxes() {
  for (i = 1; i<=8; i++){
    row_node_name = "#interest"+i;    
    row_node = cssQuery(row_node_name)[0];
    checkbox_node_name = "#checkbox" + i;
    checkbox_node= cssQuery(checkbox_node_name)[0];
    if (hasClassName(row_node, "show")) { 
      checkbox_node.checked = false;
      replaceClassName(row_node, "show", "hide");
    } else if (hasClassName(row_node, "hide")) {
      checkbox_node.checked = false;
      replaceClassName(row_node, "hide", "show");
    } else {
      //do nothing
    }
  }
}