substring to get last values

Dear All,

I have a mapping where I am using an udf for substring in PI 7.3.

I am using below udf code for substring

-----------------

String variable1="";

if (variable1!=null)

   output1 = variable1.substring(6, variable1.length());

return output1;

---------------

if the same udf is used for the other field it is not working...

-------------------
String output1="";

if (output!=null)

   output1 = output.substring(12, output.length());

return output1;

---------------

Also I tried creating function libraries also but no luck..

could any one suggest me...

Thanks and Regards,

Naveen.