Bug 201030 NPE throws out when preview the attached report design
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
/**
		 * To ease the methods compare and between. Exception with specific
		 * explanation will be thrown if anything goes wrong.
		 * 
		 * @param obj
		 * @param operands
		 * @return
		 */
		private static Object[] formatToComparable( Object obj,
				ExprTextAndValue[] operands )
		{
			Object[] obArray = new Object[operands.length + 1];
			obArray[0] = obj;
			for ( int i = 0; i < operands.length; i++ )
			{
				obArray[i + 1] = operands[i].value;
			}
			boolean isSameType = true;
			
			
			
			if ( isSameType( obj, obArray[1] ) )
			{
				for ( int i = 1; i < operands.length; i++ )
				{
					if ( obArray[i + 1] != null &&
							!isSameType( obj, obArray[i + 1] ) )
					{
						isSameType = false;
						break;