storage location not picking up while createing delivery

Hi Guru's,

While creating delivery for certain items ..the storage location is not picking up automatically in the delivery (vl01n).

If i am giving the storage location in shipping tab of salesorder,then it was picked in deliverycreation,but it should not be like that.If we dont give Storage location in salesorder then also it should pick...

Please help me in this.

Thanks & Regards

Susmitha