Application process is not getting the data from table

Question

I have created the following application process based on AJAX select value but using a pop up LOV
DECLARE
my_det VARCHAR2 (200);
BEGIN
SELECT DM_00010_CUST_NAME INTO my_det
FROM ODM_MD_00010
WHERE DM_00010_CUST_CODE = nvl(:P11_DT_00020_CUST_CODE,21);
exception when no_data_found then null;
HTP.prn (my_det);
END;
the process is getting no data found error ( hence the exception) so I am getting NULL in the name field on screen.
any help ?

Answer 1

the javascript I have in the region header is:
<script language="JavaScript" type="text/javascript">
function f_getDet ()
var get = new htmldb_Get(null,&APP_ID.,'APPLICATION_PROCESS=getDet',0);
get.add('P11_DT_00020_CUST_CODE',html_GetElement('P11_DT_00020_CUST_CODE').value)
gReturn = get.get();
if(gReturn)
{  html_GetElement('P11_DT_00020_CUST_NAME').value = gReturn  }
else
{  html_GetElement('P11_DT_00020_CUST_NAME').value = 'null'  }
get = null;
</script>