can't appearance DescriptionAltLanguage

in my receipt design i add new custom field 

and i give it this value to show translate of item product

case "ARITEMNAME":
                        returnValue = saleLine.DescriptionAltLanguage;
                        break;

into  (Retail SDK CU9) Printing> FormModulation.cs

but show me nothing how can i make it show item product on other language

*like Arabic languge for example