My stepdaughter lives in nearby Surprise, Arizona. Her husband works for a company that has many locations around the country. They got tired of the midwest snowy weather. So I guess I will go with Glendale, Ar.
Whether you are writing in business or personal style there are two ways to abbreviate state names. There are the old abbreviations like Ala., Fla. Wash., Tex., or Ore. Then there are the more commonly used Postal State Abbreviations which consist of two capital letters and no period, such as AL, FL, WA, TX, or OR. There is the possible exception that exist for journalists to use an abbreviation of two letters, one capital followed by one lower case followed by a period, such as Al., Fl., Wa. Tx., or Or. This is the editor's choice so you see it only in some printed media pieces. I personally most often use the old abbreviations on anything other than an envelope. The Post Office shortened their state abbreviations with the advent of the zip code. Seven added characters to the last address line was too many for most addressing machines of the time.
We can argue back and forth if you so desire, I already acknowledged that both are correct, I did not state that you were incorrect. If you disagree with me, fine, you are perfectly entitled to. I don’t see it as being that important as to require butting heads. ~
B.H.Wilson 