QlikSense Scripting

[#1]

when i am trying to use multiple joins in qlikview scripting i am getting an error as syntax (missing operator)

Fact:

LOAD `Ad_ID`,

    `Cost_Element_Name` as Cost_ID,

    `Cost_Source` as ExpenseSource_ID,

    `Cost_Amount`,

    `Prod_ID`;

SQL SELECT b.Ad_ID,

    a.Cost_Element_Name,

    a.Cost_Source,

    a.Cost_Amount,

    d.Prod_ID

FROM Input_4_Expense a

inner join Input_1_Ad b on a.Ad_ID = b.Ad_ID

inner join Input_2_AdProdCo c on c.Ad_Name = c.Ad_Name inner join Tb3_ProdCompany d

on d.Prod_Name = c.Prod_Name;