IF with multiple values for a variable

Okay, I know this has got to be easy but it's not working any way I try it. When a record is selected it opens up a new page. My query will display the specific results based on the type of record selected. There can be multiple values in each if. However I am having a brain fart in my if statement assigning the multiple values. Here is my if statement: if ($type == 'T','D','L' { $get_id.=" payment_request WHERE id = '$payment_id'"; } However this does not return ant results. I've tried if ($type = array('T','D','L'), if ($type == array('T','D','L'), if ($type == 'T,D,L'), if ($type == 'T' or 'D' or 'L' I also looked in the PHP manual for examples of if's and didn't find any help. I can get it to work if I create a seperate if statement for each type condition but i would prefer to not duplicate my code just to add a seperate $type