How to change field SITE using Work_order field value?

How to change field SITE using Work_order field value?

Hi!

I'm trying to set scenario on incident form. I want to fill up field SITE for all users from additional field. 
Additional field is a drop-down list, so I trying to recieve Value, not Text.

It's look like that:
var x=$CS.getValue("WorkOrder_Fields_UDF_CHAR4");
$CS.setValue("SITE", x ); 

Where I do wrong?

Thanks!
 

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