SQL query help

I can't figure out why my SQL code isn't working. I am trying to add three tables. Thank you

SELECT    

dbo.RM20101.DOCDATE,

dbo.RM20101.ORTRXAMT,  

dbo.RM20101.DOCNUMBR,

dbo.RM00101.CUSTNAME,

dbo.RM00101.CUSTCLAS,

dbo.RM20101.CHEKNMBR,

dbo.RM00101.SLPRSNID,

dbo.RM20101.CSPORNBR,

dbo.RM00301.SLPRSNFN,

dbo.RM00301.SPRSNSLN

FROM        

dbo.RM00101 with (nolock)

INNER JOIN

dbo.RM20101 with (nolock) ON dbo.RM00101.CUSTNMBR = dbo.RM20101.CUSTNMBR

dbo.RM00301 with (nolock) ON dbo.RM00301.SLPRSNID = dbo.RM20101.SLPRSNID