This function deletes table object attribute attrName from table object toid by resetting the markup from which the attribute was derived to a default value.

If toid or attrName is invalid, the function returns a zero (0). If the function executes successfully, it returns a one (1).

The toid parameter is the table object ID of the table object whose attribute value is to be deleted. The attrName parameter is a string for the name of the attribute. Note that names are case insensitive.