void deleteRule(unsigned long index) throws DOMException;
index
The position within the @media rule block of the rule to be deleted.
This method throws a DOMException with one of the following code values in the following circumstances:
INDEX_SIZE_ERR
index is negative or is greater than or equal to the number of rules in cssRules.
NO_MODIFICATION_ALLOWED_ERR
The rule is read-only.
This method deletes the rule at the specified position in the cssRules array.