php - MySQL Drop Multiple Columns -

i'm trying drop multiple columns, having trouble. syntax below works when alter table , add multiple values in brackets () doesn't work drop column. using wrong syntax?

    $table3 = "         alter table $table3_name         drop column (             user_firstname,             user_lastname,             user_address,             user_address2,             user_city,             user_state,             user_zip,             user_phone         );     "; 

alter table `tablename` drop `column1`, drop `column2`, drop `column3`;