ActionScript 3.0 :: Pass Multiple Variables From Flash To MySQL With PHP

When I pass a single variable (telephone) from Flash using the below it works fine

var xmlSaveLoader:URLLoader = new URLLoader();
xmlSaveLoader.load(new URLRequest("customer_insert.php?telephone="+teleph one));

I can read the variable in PHP using $key_telephone = $HTTP_GET_VARS[telephone];

and then run sql command to insert into table customers mysql_query("INSERT into customers (telephone) values ($key_telephone) ");

However, I have a problem and don't know how to pass multiple variables to PHP. I tried the following to pass a second variable (first_name)but it doesn't seem to work... xmlSaveLoader.load(new URLRequest("customer_insert.php?telephone="+teleph one+"&first_name="+first_name));