2 columns on 1 table that have same join

New to this so bear with me.
I have a 2 tables
Table 1 has SupplierNumber and AltSupplierNo

I need to join both of these columns to Table2 to bring back the supplier names twice. Once beside SupplierNumber and again beside AltSupplierNumber

I cant get this to work
thanks all

Code Below

SELECT 
    PDDOCO as OrderNumber, 
    PDMCU as Branch,
    PDAN8 as SupplierNumber,   (first supplier number)
    ABALPH as SupplierName,
    PDANCR as AltSupplierNo,   (Alternate supplier number)
    ABALPH as AltSupplierName,
FROM system.Table1
JOIN system.Table2 ON system.Table1.PDAN8=system.Table2.Supplier
WHERE PDUOPN > 0;

When joining multiple tables, and in particular when needed to join a single table more then once: use table aliases so that you can specify which tabe the columns columns are to come from. Do this for all tables in the query, and prefix every column reference with the approriate alias.

SELECT
      t.PDDOCO AS OrderNumber
    , t.PDMCU AS Branch
    , t.PDAN8 AS SupplierNumber -- (first supplier number) 
    , s1.ABALPH AS SupplierName
    , t.PDANCR AS AltSupplierNo -- (Alternate supplier number) 
    , s2.ABALPH AS AltSupplierName
FROM system.Table1 AS t
    INNER JOIN system.Table2 AS s1 ON t.PDAN8 = s1.Supplier
    LEFT JOIN system.Table2 AS s2 ON t.PDANCR = s2.Supplier
WHERE t.PDUOPN > 0

Note: I have assumed that some rows might not have an alternative supplier, hence the second join uses a left join.

Also: all the column references above are a guess, some may be wrong