Bug 204229 [Automation][Regression]Exception is thrown when preview reportdesign in webviewer
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/RDSave.java
&& binding.getAggregatOns( ).size( ) == 0
					&& binding.getAggrFunction( ) == null )
			{
				IBaseExpression expr = binding.getExpression( );
				if( expr instanceof IScriptExpression )
				{
					String expression = ((IScriptExpression)expr).getText( );
					String dataSetColumnName = this.getDataSetColumnName( expression );
					if( dataSetColumnName!= null )
					{
						bindingNameColumnName.put( binding.getBindingName( ),
								dataSetColumnName );
					}
				}
			}
			if( bindingNameColumnName.get( binding.getBindingName( ) ) == null )
				bindingNamesToSave.add( binding.getBindingName( ) );
		}
		this.rowSaveUtil = new RowSaveUtil( rowCount,
				rowExprsOs,
				rowLenOs,
				bindingNamesToSave,
				bindingNameColumnName, this.streamManager.getVersion( ) );
	}
	
	/**
	 * 
	 * @param expr
	 * @return
	 */