Underline table for fields in std datasources

Hi All,

I want to know how I can find out the tabe name form which datasource field is coming?

Say for eg , i have data source 2LIS_11_VAITM ? in that I have field VBELN right, and in RSA5/RSA6 I can see that datasource it open up list of files and Extract Structure MC11VA0ITM and when go and check that MC11VA0ITM by double clicking it .. it shows me all fields .. But now my problem is to find out underline table for that field, as form which tables that field is coming..?

I can get that information help.sap.com in datasource help, but I want to find out in system itself.

Please help me .

Regards

Ashutosh D