Problem with validation integer element in XML document

Hi All,

I have created the following test.xml and test.xsd in jdeveloper 11g. The xsd properly does all checks. However, it does not accept null in LINENUMBER element (integer) even though I put nillable=true. It gives error:  XML-24525: (Error) Invalid text '' in element: 'LINENUMBER'.

This problem does not occur for the ORDERNUMBER element (string). I can have null or up to 2 characters.

How can I set the XSD for LINENUMBER element to accept either null or maximum 5 digits number? Can anyone help please?     

Thanks,

Majid

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Test.XSD

<?xml version="1.0" encoding="windows-1252" ?>
<xsd:schema xmlns:xsd="