Bug 119331 Library - name space terminology and behavior
During BIRT 2.0 library feature review meeting the following change was decided. - Change the term namespace to 'prefix' - By default use the library name as the prefix ( namespace ); the dialog to input prefix should be prompted only if hte auto generated prefix is not unique.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dnd/InsertInLayoutUtil.java
else if ( insertObj instanceof DataSetItemModel )
		{
			return handleValidateDataSetColumn( (DataSetItemModel) insertObj,
					targetPart );
		}
		else if ( insertObj instanceof ScalarParameterHandle )
		{
			return isHandleValid( (ScalarParameterHandle) insertObj )
					&& handleValidateParameter( targetPart );
		}
		return false;
	}
	/**
	 * Checks if all the DataSetColumn has the same DataSet.
	 * 
	 * @param array
	 *            all elements
	 * @return false if not same; true if every column has the same DataSet or
	 *         the element is not an instance of DataSetColumn
	 */
	protected static boolean checkSameDataSetInMultiColumns( Object[] array )
	{
		if ( array == null )
			return false;
		Object dataSet = null;
		for ( int i = 0; i < array.length; i++ )
		{
			if ( array[i] instanceof DataSetItemModel )
			{
				Object currDataSet = ( (DataSetItemModel) array[i] ).getParent( );