Class And Id Attributes Are Lowercase With Underscore Separator
JavaScript can access elements by their ID attribute and class names. When assigning IDs and class names with multiple words, these should also be separated by an underscore (same as variables).
Good Example:
element.setAttribute("class", "my_class");
or
<div class="my_class" />
Bad Example:
element.setAttribute("class", "myClass");
or
<div class="myClass" />