Goods Issue based on batch number

Hi gurus,

                I have batch managed for a material and maintained SLED too. When i do GR it is done in batches.

                Client has a requirement, when they issue using mvt type 201, the issue must be done by FIFO method. The batch received first must be issued first. If we select wrong batch it must throw a warning message.

                As per my knowledge i have created characteristics by adding the table and field, 'manufacturing date(in GR under batch tab)', assigned it to class, and sort sequence as ascending.

                But when I do GI it is picking any batch without warning.

                Please help me solve this.

Thanks

Sathish