fixed empty number field value

SE/se-lib/TableAjax.php.TableAjax.js

@@ -1255,8 +1255,8 @@ var TableAjax = function() {
 					// console.log('FieldWidget: generate function to render field('+_fieldName+') _fractionDigits('+_fractionDigits+')', fieldProps);
 					return function(val, fieldPK, row) {
 						// console.log('FieldWidget: pk('+fieldPK+') run function to render field('+_fieldName+') with value('+val+') ', fieldProps);
-						if ('' === val) return null; // is nullable
-						if ('*****' === val) return val
+						if ('' === val) return ''; // is nullable
+						if ('*****' === val) return val;
 						// enumeration
 						// fractionDigits
 						// maxExclusive