Index: Retrieve a value from the file name

General

Our file is named TEST_005.pdf, our goal is to retrieve the value 005 which corresponds to our invoice number

Script

var ws = new JSE_WebService("127.0.0.1", "http", 8090);
var res = ws.send("/ws/document/"+INTERNAL_DOCUMENT_ID, "GET", {"Authorization" : "Bearer "+ CAPTURE_WS_TOKEN});
var docName = JSON.parse(res.StringResponse).filename;
if(docName != null){
    var nameWithoutExt = docName.split(".");
     
    if(nameWithoutExt.length > 0){
        var values = nameWithoutExt[0].split("_");
     
        if(values.length > 1)
            return values[1];
    }
}
 
return "";